diff --git a/exercises/practice/allergies/.docs/instructions.md b/exercises/practice/allergies/.docs/instructions.md
index c21af3313..a13949209 100644
--- a/exercises/practice/allergies/.docs/instructions.md
+++ b/exercises/practice/allergies/.docs/instructions.md
@@ -6,21 +6,21 @@ An allergy test produces a single numeric score which contains the information a
 
 The list of items (and their value) that were tested are:
 
-* eggs (1)
-* peanuts (2)
-* shellfish (4)
-* strawberries (8)
-* tomatoes (16)
-* chocolate (32)
-* pollen (64)
-* cats (128)
+- eggs (1)
+- peanuts (2)
+- shellfish (4)
+- strawberries (8)
+- tomatoes (16)
+- chocolate (32)
+- pollen (64)
+- cats (128)
 
 So if Tom is allergic to peanuts and chocolate, he gets a score of 34.
 
 Now, given just that score of 34, your program should be able to say:
 
-* Whether Tom is allergic to any one of those allergens listed above.
-* All the allergens Tom is allergic to.
+- Whether Tom is allergic to any one of those allergens listed above.
+- All the allergens Tom is allergic to.
 
 Note: a given score may include allergens **not** listed above (i.e.  allergens that score 256, 512, 1024, etc.).
 Your program should ignore those components of the score.
diff --git a/exercises/practice/allergies/.meta/config.json b/exercises/practice/allergies/.meta/config.json
index c11e43f69..cfddaa93e 100644
--- a/exercises/practice/allergies/.meta/config.json
+++ b/exercises/practice/allergies/.meta/config.json
@@ -26,6 +26,6 @@
     ]
   },
   "blurb": "Given a person's allergy score, determine whether or not they're allergic to a given item, and their full list of allergies.",
-  "source": "Jumpstart Lab Warm-up",
-  "source_url": "http://jumpstartlab.com"
+  "source": "Exercise by the JumpstartLab team for students at The Turing School of Software and Design.",
+  "source_url": "https://turing.edu"
 }
diff --git a/exercises/practice/atbash-cipher/.meta/config.json b/exercises/practice/atbash-cipher/.meta/config.json
index 48f547192..c858dc336 100644
--- a/exercises/practice/atbash-cipher/.meta/config.json
+++ b/exercises/practice/atbash-cipher/.meta/config.json
@@ -27,5 +27,5 @@
   },
   "blurb": "Create an implementation of the atbash cipher, an ancient encryption system created in the Middle East.",
   "source": "Wikipedia",
-  "source_url": "http://en.wikipedia.org/wiki/Atbash"
+  "source_url": "https://en.wikipedia.org/wiki/Atbash"
 }
diff --git a/exercises/practice/beer-song/.meta/config.json b/exercises/practice/beer-song/.meta/config.json
index 67b05f125..2059c03f2 100644
--- a/exercises/practice/beer-song/.meta/config.json
+++ b/exercises/practice/beer-song/.meta/config.json
@@ -27,5 +27,5 @@
   },
   "blurb": "Produce the lyrics to that beloved classic, that field-trip favorite: 99 Bottles of Beer on the Wall.",
   "source": "Learn to Program by Chris Pine",
-  "source_url": "http://pine.fm/LearnToProgram/?Chapter=06"
+  "source_url": "https://pine.fm/LearnToProgram/?Chapter=06"
 }
diff --git a/exercises/practice/binary-search/.docs/instructions.md b/exercises/practice/binary-search/.docs/instructions.md
index d7f1c8992..aa1946cfb 100644
--- a/exercises/practice/binary-search/.docs/instructions.md
+++ b/exercises/practice/binary-search/.docs/instructions.md
@@ -11,7 +11,7 @@ Binary search only works when a list has been sorted.
 
 The algorithm looks like this:
 
-- Find the middle element of a sorted list and compare it with the item we're looking for.
+- Find the middle element of a *sorted* list and compare it with the item we're looking for.
 - If the middle element is our item, then we're done!
 - If the middle element is greater than our item, we can eliminate that element and all the elements **after** it.
 - If the middle element is less than our item, we can eliminate that element and all the elements **before** it.
diff --git a/exercises/practice/binary-search/.meta/config.json b/exercises/practice/binary-search/.meta/config.json
index 8a1e3d9f6..1c180c4e7 100644
--- a/exercises/practice/binary-search/.meta/config.json
+++ b/exercises/practice/binary-search/.meta/config.json
@@ -26,5 +26,5 @@
   },
   "blurb": "Implement a binary search algorithm.",
   "source": "Wikipedia",
-  "source_url": "http://en.wikipedia.org/wiki/Binary_search_algorithm"
+  "source_url": "https://en.wikipedia.org/wiki/Binary_search_algorithm"
 }
diff --git a/exercises/practice/binary/.meta/config.json b/exercises/practice/binary/.meta/config.json
index 94e8bceb2..e8a8ee487 100644
--- a/exercises/practice/binary/.meta/config.json
+++ b/exercises/practice/binary/.meta/config.json
@@ -28,5 +28,5 @@
   },
   "blurb": "Convert a binary number, represented as a string (e.g. '101010'), to its decimal equivalent using first principles.",
   "source": "All of Computer Science",
-  "source_url": "http://www.wolframalpha.com/input/?i=binary&a=*C.binary-_*MathWorld-"
+  "source_url": "https://www.wolframalpha.com/examples/mathematics/numbers/base-conversions"
 }
diff --git a/exercises/practice/bob/.meta/config.json b/exercises/practice/bob/.meta/config.json
index da7ababdf..06c58c1bc 100644
--- a/exercises/practice/bob/.meta/config.json
+++ b/exercises/practice/bob/.meta/config.json
@@ -32,5 +32,5 @@
   },
   "blurb": "Bob is a lackadaisical teenager. In conversation, his responses are very limited.",
   "source": "Inspired by the 'Deaf Grandma' exercise in Chris Pine's Learn to Program tutorial.",
-  "source_url": "http://pine.fm/LearnToProgram/?Chapter=06"
+  "source_url": "https://pine.fm/LearnToProgram/?Chapter=06"
 }
diff --git a/exercises/practice/circular-buffer/.meta/config.json b/exercises/practice/circular-buffer/.meta/config.json
index a57cc420c..3fcaef293 100644
--- a/exercises/practice/circular-buffer/.meta/config.json
+++ b/exercises/practice/circular-buffer/.meta/config.json
@@ -20,5 +20,5 @@
   },
   "blurb": "A data structure that uses a single, fixed-size buffer as if it were connected end-to-end.",
   "source": "Wikipedia",
-  "source_url": "http://en.wikipedia.org/wiki/Circular_buffer"
+  "source_url": "https://en.wikipedia.org/wiki/Circular_buffer"
 }
diff --git a/exercises/practice/crypto-square/.docs/instructions.md b/exercises/practice/crypto-square/.docs/instructions.md
index 8a489f6e2..6c3826ee5 100644
--- a/exercises/practice/crypto-square/.docs/instructions.md
+++ b/exercises/practice/crypto-square/.docs/instructions.md
@@ -4,11 +4,10 @@ Implement the classic method for composing secret messages called a square code.
 
 Given an English text, output the encoded version of that text.
 
-First, the input is normalized: the spaces and punctuation are removed
-from the English text and the message is down-cased.
+First, the input is normalized: the spaces and punctuation are removed from the English text and the message is down-cased.
 
-Then, the normalized characters are broken into rows. These rows can be
-regarded as forming a rectangle when printed with intervening newlines.
+Then, the normalized characters are broken into rows.
+These rows can be regarded as forming a rectangle when printed with intervening newlines.
 
 For example, the sentence
 
@@ -22,18 +21,16 @@ is normalized to:
 "ifmanwasmeanttostayonthegroundgodwouldhavegivenusroots"
 ```
 
-The plaintext should be organized in to a rectangle. The size of the
-rectangle should be decided by the length of the message.
+The plaintext should be organized into a rectangle as square as possible.
+The size of the rectangle should be decided by the length of the message.
 
-If `c` is the number of columns and `r` is the number of rows, then for
-the rectangle `r` x `c` find the smallest possible integer `c` such that:
+If `c` is the number of columns and `r` is the number of rows, then for the rectangle `r` x `c` find the smallest possible integer `c` such that:
 
-- `r * c >= length(message)`,
+- `r * c >= length of message`,
 - and `c >= r`,
 - and `c - r <= 1`.
 
-Our normalized text is 54 characters long, dictating a rectangle with
-`c = 8` and `r = 7`:
+Our normalized text is 54 characters long, dictating a rectangle with `c = 8` and `r = 7`:
 
 ```text
 "ifmanwas"
@@ -45,8 +42,7 @@ Our normalized text is 54 characters long, dictating a rectangle with
 "sroots  "
 ```
 
-The coded message is obtained by reading down the columns going left to
-right.
+The coded message is obtained by reading down the columns going left to right.
 
 The message above is coded as:
 
@@ -54,17 +50,14 @@ The message above is coded as:
 "imtgdvsfearwermayoogoanouuiontnnlvtwttddesaohghnsseoau"
 ```
 
-Output the encoded text in chunks that fill perfect rectangles `(r X c)`,
-with `c` chunks of `r` length, separated by spaces. For phrases that are
-`n` characters short of the perfect rectangle, pad each of the last `n`
-chunks with a single trailing space.
+Output the encoded text in chunks that fill perfect rectangles `(r X c)`, with `c` chunks of `r` length, separated by spaces.
+For phrases that are `n` characters short of the perfect rectangle, pad each of the last `n` chunks with a single trailing space.
 
 ```text
 "imtgdvs fearwer mayoogo anouuio ntnnlvt wttddes aohghn  sseoau "
 ```
 
-Notice that were we to stack these, we could visually decode the
-ciphertext back in to the original message:
+Notice that were we to stack these, we could visually decode the ciphertext back in to the original message:
 
 ```text
 "imtgdvs"
diff --git a/exercises/practice/crypto-square/.meta/config.json b/exercises/practice/crypto-square/.meta/config.json
index 747b34ee5..17c6c5b20 100644
--- a/exercises/practice/crypto-square/.meta/config.json
+++ b/exercises/practice/crypto-square/.meta/config.json
@@ -25,5 +25,5 @@
   },
   "blurb": "Implement the classic method for composing secret messages called a square code.",
   "source": "J Dalbey's Programming Practice problems",
-  "source_url": "http://users.csc.calpoly.edu/~jdalbey/103/Projects/ProgrammingPractice.html"
+  "source_url": "https://users.csc.calpoly.edu/~jdalbey/103/Projects/ProgrammingPractice.html"
 }
diff --git a/exercises/practice/darts/.docs/instructions.md b/exercises/practice/darts/.docs/instructions.md
index 3cab42905..70f0e53da 100644
--- a/exercises/practice/darts/.docs/instructions.md
+++ b/exercises/practice/darts/.docs/instructions.md
@@ -6,18 +6,18 @@ Write a function that returns the earned points in a single toss of a Darts game
 
 In our particular instance of the game, the target rewards 4 different amounts of points, depending on where the dart lands:
 
-* If the dart lands outside the target, player earns no points (0 points).
-* If the dart lands in the outer circle of the target, player earns 1 point.
-* If the dart lands in the middle circle of the target, player earns 5 points.
-* If the dart lands in the inner circle of the target, player earns 10 points.
+- If the dart lands outside the target, player earns no points (0 points).
+- If the dart lands in the outer circle of the target, player earns 1 point.
+- If the dart lands in the middle circle of the target, player earns 5 points.
+- If the dart lands in the inner circle of the target, player earns 10 points.
 
 The outer circle has a radius of 10 units (this is equivalent to the total radius for the entire target), the middle circle a radius of 5 units, and the inner circle a radius of 1.
-Of course, they are all centered at the same point (that is, the circles are [concentric][] defined by the coordinates (0, 0).
+Of course, they are all centered at the same point — that is, the circles are [concentric][] defined by the coordinates (0, 0).
 
 Write a function that given a point in the target (defined by its [Cartesian coordinates][cartesian-coordinates] `x` and `y`, where `x` and `y` are [real][real-numbers]), returns the correct amount earned by a dart landing at that point.
 
 [darts]: https://en.wikipedia.org/wiki/Darts
 [darts-target]: https://en.wikipedia.org/wiki/Darts#/media/File:Darts_in_a_dartboard.jpg
-[concentric]: http://mathworld.wolfram.com/ConcentricCircles.html
+[concentric]: https://mathworld.wolfram.com/ConcentricCircles.html
 [cartesian-coordinates]: https://www.mathsisfun.com/data/cartesian-coordinates.html
 [real-numbers]: https://www.mathsisfun.com/numbers/real-numbers.html
diff --git a/exercises/practice/diamond/.docs/instructions.md b/exercises/practice/diamond/.docs/instructions.md
index ae50fcb22..3034802fe 100644
--- a/exercises/practice/diamond/.docs/instructions.md
+++ b/exercises/practice/diamond/.docs/instructions.md
@@ -5,17 +5,17 @@ Given a letter, it prints a diamond starting with 'A', with the supplied letter
 
 ## Requirements
 
-* The first row contains one 'A'.
-* The last row contains one 'A'.
-* All rows, except the first and last, have exactly two identical letters.
-* All rows have as many trailing spaces as leading spaces. (This might be 0).
-* The diamond is horizontally symmetric.
-* The diamond is vertically symmetric.
-* The diamond has a square shape (width equals height).
-* The letters form a diamond shape.
-* The top half has the letters in ascending order.
-* The bottom half has the letters in descending order.
-* The four corners (containing the spaces) are triangles.
+- The first row contains one 'A'.
+- The last row contains one 'A'.
+- All rows, except the first and last, have exactly two identical letters.
+- All rows have as many trailing spaces as leading spaces. (This might be 0).
+- The diamond is horizontally symmetric.
+- The diamond is vertically symmetric.
+- The diamond has a square shape (width equals height).
+- The letters form a diamond shape.
+- The top half has the letters in ascending order.
+- The bottom half has the letters in descending order.
+- The four corners (containing the spaces) are triangles.
 
 ## Examples
 
diff --git a/exercises/practice/diamond/.meta/config.json b/exercises/practice/diamond/.meta/config.json
index b72e44f41..c854d01aa 100644
--- a/exercises/practice/diamond/.meta/config.json
+++ b/exercises/practice/diamond/.meta/config.json
@@ -24,5 +24,5 @@
   },
   "blurb": "Given a letter, print a diamond starting with 'A' with the supplied letter at the widest point.",
   "source": "Seb Rose",
-  "source_url": "http://claysnow.co.uk/recycling-tests-in-tdd/"
+  "source_url": "https://web.archive.org/web/20220807163751/http://claysnow.co.uk/recycling-tests-in-tdd/"
 }
diff --git a/exercises/practice/difference-of-squares/.meta/config.json b/exercises/practice/difference-of-squares/.meta/config.json
index 4f5256041..5ee67ac22 100644
--- a/exercises/practice/difference-of-squares/.meta/config.json
+++ b/exercises/practice/difference-of-squares/.meta/config.json
@@ -27,5 +27,5 @@
   },
   "blurb": "Find the difference between the square of the sum and the sum of the squares of the first N natural numbers.",
   "source": "Problem 6 at Project Euler",
-  "source_url": "http://projecteuler.net/problem=6"
+  "source_url": "https://projecteuler.net/problem=6"
 }
diff --git a/exercises/practice/etl/.meta/config.json b/exercises/practice/etl/.meta/config.json
index 8ea6236f4..1e53d08db 100644
--- a/exercises/practice/etl/.meta/config.json
+++ b/exercises/practice/etl/.meta/config.json
@@ -22,7 +22,7 @@
       ".meta/example.h"
     ]
   },
-  "blurb": "We are going to do the `Transform` step of an Extract-Transform-Load.",
-  "source": "The Jumpstart Lab team",
-  "source_url": "http://jumpstartlab.com"
+  "blurb": "Change the data format for scoring a game to more easily add other languages.",
+  "source": "Based on an exercise by the JumpstartLab team for students at The Turing School of Software and Design.",
+  "source_url": "https://turing.edu"
 }
diff --git a/exercises/practice/gigasecond/.docs/introduction.md b/exercises/practice/gigasecond/.docs/introduction.md
index 74afaa994..18a3dc200 100644
--- a/exercises/practice/gigasecond/.docs/introduction.md
+++ b/exercises/practice/gigasecond/.docs/introduction.md
@@ -13,7 +13,7 @@ Then we can use metric system prefixes for writing large numbers of seconds in m
 - Perhaps you and your family would travel to somewhere exotic for two megaseconds (that's two million seconds).
 - And if you and your spouse were married for _a thousand million_ seconds, you would celebrate your one gigasecond anniversary.
 
-```exercism/note
+~~~~exercism/note
 If we ever colonize Mars or some other planet, measuring time is going to get even messier.
 If someone says "year" do they mean a year on Earth or a year on Mars?
 
@@ -21,4 +21,4 @@ The idea for this exercise came from the science fiction novel ["A Deepness in t
 In it the author uses the metric system as the basis for time measurements.
 
 [vinge-novel]: https://www.tor.com/2017/08/03/science-fiction-with-something-for-everyone-a-deepness-in-the-sky-by-vernor-vinge/
-```
+~~~~
diff --git a/exercises/practice/gigasecond/.meta/config.json b/exercises/practice/gigasecond/.meta/config.json
index 9934029dc..29e9d25ae 100644
--- a/exercises/practice/gigasecond/.meta/config.json
+++ b/exercises/practice/gigasecond/.meta/config.json
@@ -28,5 +28,5 @@
   },
   "blurb": "Given a moment, determine the moment that would be after a gigasecond has passed.",
   "source": "Chapter 9 in Chris Pine's online Learn to Program tutorial.",
-  "source_url": "http://pine.fm/LearnToProgram/?Chapter=09"
+  "source_url": "https://pine.fm/LearnToProgram/?Chapter=09"
 }
diff --git a/exercises/practice/grains/.meta/config.json b/exercises/practice/grains/.meta/config.json
index d7eb9bbb9..9c947a9db 100644
--- a/exercises/practice/grains/.meta/config.json
+++ b/exercises/practice/grains/.meta/config.json
@@ -27,6 +27,6 @@
     ]
   },
   "blurb": "Calculate the number of grains of wheat on a chessboard given that the number on each square doubles.",
-  "source": "JavaRanch Cattle Drive, exercise 6",
-  "source_url": "http://www.javaranch.com/grains.jsp"
+  "source": "The CodeRanch Cattle Drive, Assignment 6",
+  "source_url": "https://coderanch.com/wiki/718824/Grains"
 }
diff --git a/exercises/practice/hamming/.meta/config.json b/exercises/practice/hamming/.meta/config.json
index 2c002775a..283d2e941 100644
--- a/exercises/practice/hamming/.meta/config.json
+++ b/exercises/practice/hamming/.meta/config.json
@@ -34,5 +34,5 @@
   },
   "blurb": "Calculate the Hamming difference between two DNA strands.",
   "source": "The Calculating Point Mutations problem at Rosalind",
-  "source_url": "http://rosalind.info/problems/hamm/"
+  "source_url": "https://rosalind.info/problems/hamm/"
 }
diff --git a/exercises/practice/hello-world/.docs/instructions.md b/exercises/practice/hello-world/.docs/instructions.md
index 8b5568479..c9570e48a 100644
--- a/exercises/practice/hello-world/.docs/instructions.md
+++ b/exercises/practice/hello-world/.docs/instructions.md
@@ -13,4 +13,4 @@ The objectives are simple:
 
 If everything goes well, you will be ready to fetch your first real exercise.
 
-[hello-world]: http://en.wikipedia.org/wiki/%22Hello,_world!%22_program
+[hello-world]: https://en.wikipedia.org/wiki/%22Hello,_world!%22_program
diff --git a/exercises/practice/hello-world/.meta/config.json b/exercises/practice/hello-world/.meta/config.json
index 7d887db51..d93a0d3be 100644
--- a/exercises/practice/hello-world/.meta/config.json
+++ b/exercises/practice/hello-world/.meta/config.json
@@ -29,5 +29,5 @@
   },
   "blurb": "The classical introductory exercise. Just say \"Hello, World!\".",
   "source": "This is an exercise to introduce users to using Exercism",
-  "source_url": "http://en.wikipedia.org/wiki/%22Hello,_world!%22_program"
+  "source_url": "https://en.wikipedia.org/wiki/%22Hello,_world!%22_program"
 }
diff --git a/exercises/practice/largest-series-product/.meta/config.json b/exercises/practice/largest-series-product/.meta/config.json
index cedb650b8..784a316f2 100644
--- a/exercises/practice/largest-series-product/.meta/config.json
+++ b/exercises/practice/largest-series-product/.meta/config.json
@@ -26,5 +26,5 @@
   },
   "blurb": "Given a string of digits, calculate the largest product for a contiguous substring of digits of length n.",
   "source": "A variation on Problem 8 at Project Euler",
-  "source_url": "http://projecteuler.net/problem=8"
+  "source_url": "https://projecteuler.net/problem=8"
 }
diff --git a/exercises/practice/leap/.docs/instructions.md b/exercises/practice/leap/.docs/instructions.md
index 36ce86bbd..a83826b2e 100644
--- a/exercises/practice/leap/.docs/instructions.md
+++ b/exercises/practice/leap/.docs/instructions.md
@@ -19,4 +19,4 @@ Though our exercise adopts some very simple rules, there is more to learn!
 
 For a delightful, four minute explanation of the whole leap year phenomenon, go watch [this youtube video][video].
 
-[video]: http://www.youtube.com/watch?v=xX96xng7sAE
+[video]: https://www.youtube.com/watch?v=xX96xng7sAE
diff --git a/exercises/practice/leap/.meta/config.json b/exercises/practice/leap/.meta/config.json
index f9ebe21ce..a41a8fefa 100644
--- a/exercises/practice/leap/.meta/config.json
+++ b/exercises/practice/leap/.meta/config.json
@@ -30,6 +30,6 @@
     ]
   },
   "blurb": "Given a year, report if it is a leap year.",
-  "source": "JavaRanch Cattle Drive, exercise 3",
-  "source_url": "http://www.javaranch.com/leap.jsp"
+  "source": "CodeRanch Cattle Drive, Assignment 3",
+  "source_url": "https://coderanch.com/t/718816/Leap"
 }
diff --git a/exercises/practice/linked-list/.docs/instructions.md b/exercises/practice/linked-list/.docs/instructions.md
index a47942d73..edf4055b3 100644
--- a/exercises/practice/linked-list/.docs/instructions.md
+++ b/exercises/practice/linked-list/.docs/instructions.md
@@ -13,7 +13,7 @@ Sometimes a station gets closed down, and in that case the station needs to be r
 
 The size of a route is measured not by how far the train travels, but by how many stations it stops at.
 
-```exercism/note
+~~~~exercism/note
 The linked list is a fundamental data structure in computer science, often used in the implementation of other data structures.
 As the name suggests, it is a list of nodes that are linked together.
 It is a list of "nodes", where each node links to its neighbor or neighbors.
@@ -23,4 +23,4 @@ In a **doubly linked list** each node links to both the node that comes before,
 If you want to dig deeper into linked lists, check out [this article][intro-linked-list] that explains it using nice drawings.
 
 [intro-linked-list]: https://medium.com/basecs/whats-a-linked-list-anyway-part-1-d8b7e6508b9d
-```
+~~~~
diff --git a/exercises/practice/list-ops/.docs/instructions.md b/exercises/practice/list-ops/.docs/instructions.md
index 1779573d9..ccfc2f8b2 100644
--- a/exercises/practice/list-ops/.docs/instructions.md
+++ b/exercises/practice/list-ops/.docs/instructions.md
@@ -7,11 +7,13 @@ Implement a series of basic list operations, without using existing functions.
 
 The precise number and names of the operations to be implemented will be track dependent to avoid conflicts with existing names, but the general operations you will implement include:
 
-* `append` (*given two lists, add all items in the second list to the end of the first list*);
-* `concatenate` (*given a series of lists, combine all items in all lists into one flattened list*);
-* `filter` (*given a predicate and a list, return the list of all items for which `predicate(item)` is True*);
-* `length` (*given a list, return the total number of items within it*);
-* `map` (*given a function and a list, return the list of the results of applying `function(item)` on all items*);
-* `foldl` (*given a function, a list, and initial accumulator, fold (reduce) each item into the accumulator from the left using `function(accumulator, item)`*);
-* `foldr` (*given a function, a list, and an initial accumulator, fold (reduce) each item into the accumulator from the right using `function(item, accumulator)`*);
-* `reverse` (*given a list, return a list with all the original items, but in reversed order*);
+- `append` (*given two lists, add all items in the second list to the end of the first list*);
+- `concatenate` (*given a series of lists, combine all items in all lists into one flattened list*);
+- `filter` (*given a predicate and a list, return the list of all items for which `predicate(item)` is True*);
+- `length` (*given a list, return the total number of items within it*);
+- `map` (*given a function and a list, return the list of the results of applying `function(item)` on all items*);
+- `foldl` (*given a function, a list, and initial accumulator, fold (reduce) each item into the accumulator from the left*);
+- `foldr` (*given a function, a list, and an initial accumulator, fold (reduce) each item into the accumulator from the right*);
+- `reverse` (*given a list, return a list with all the original items, but in reversed order*).
+
+Note, the ordering in which arguments are passed to the fold functions (`foldl`, `foldr`) is significant.
diff --git a/exercises/practice/luhn/.meta/config.json b/exercises/practice/luhn/.meta/config.json
index 45a5498e2..fc716c398 100644
--- a/exercises/practice/luhn/.meta/config.json
+++ b/exercises/practice/luhn/.meta/config.json
@@ -24,5 +24,5 @@
   },
   "blurb": "Given a number determine whether or not it is valid per the Luhn formula.",
   "source": "The Luhn Algorithm on Wikipedia",
-  "source_url": "http://en.wikipedia.org/wiki/Luhn_algorithm"
+  "source_url": "https://en.wikipedia.org/wiki/Luhn_algorithm"
 }
diff --git a/exercises/practice/matching-brackets/.docs/instructions.md b/exercises/practice/matching-brackets/.docs/instructions.md
index ca7c8d838..544daa968 100644
--- a/exercises/practice/matching-brackets/.docs/instructions.md
+++ b/exercises/practice/matching-brackets/.docs/instructions.md
@@ -1,3 +1,4 @@
 # Instructions
 
 Given a string containing brackets `[]`, braces `{}`, parentheses `()`, or any combination thereof, verify that any and all pairs are matched and nested correctly.
+The string may also contain other characters, which for the purposes of this exercise should be ignored.
diff --git a/exercises/practice/meetup/.docs/instructions.md b/exercises/practice/meetup/.docs/instructions.md
index 788f9f7c6..0694ef583 100644
--- a/exercises/practice/meetup/.docs/instructions.md
+++ b/exercises/practice/meetup/.docs/instructions.md
@@ -1,19 +1,51 @@
 # Instructions
 
-In this exercise, you will be given a general description of a meetup date and then asked to find the actual meetup date.
+Recurring monthly meetups are generally scheduled on the given weekday of a given week each month.
+In this exercise you will be given the recurring schedule, along with a month and year, and then asked to find the exact date of the meetup.
 
-Examples of general descriptions are:
+For example a meetup might be scheduled on the _first Monday_ of every month.
+You might then be asked to find the date that this meetup will happen in January 2018.
+In other words, you need to determine the date of the first Monday of January 2018.
 
-- First Monday of January 2022
-- Third Tuesday of August 2021
-- Teenth Wednesday of May 2022
-- Teenth Sunday of July 2021
-- Last Thursday of November 2021
+Similarly, you might be asked to find:
+
+- the third Tuesday of August 2019 (August 20, 2019)
+- the teenth Wednesday of May 2020 (May 13, 2020)
+- the fourth Sunday of July 2021 (July 25, 2021)
+- the last Thursday of November 2022 (November 24, 2022)
 
 The descriptors you are expected to process are: `first`, `second`, `third`, `fourth`, `last`, `teenth`.
 
 Note that descriptor `teenth` is a made-up word.
-There are exactly seven numbered days in a month that end with "teenth" ("thirteenth" to "nineteenth").
-Therefore, it is guaranteed that each day of the week (Monday, Tuesday, ...) will have exactly one numbered day ending with "teenth" each month.
 
-For example, if given "First Monday of January 2022", the correct meetup date is January 3, 2022.
+It refers to the seven numbers that end in '-teen' in English: 13, 14, 15, 16, 17, 18, and 19.
+But general descriptions of dates use ordinal numbers, e.g. the _first_ Monday, the _third_ Tuesday.
+
+For the numbers ending in '-teen', that becomes:
+
+- 13th (thirteenth)
+- 14th (fourteenth)
+- 15th (fifteenth)
+- 16th (sixteenth)
+- 17th (seventeenth)
+- 18th (eighteenth)
+- 19th (nineteenth)
+
+So there are seven numbers ending in '-teen'.
+And there are also seven weekdays (Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday).
+Therefore, it is guaranteed that each day of the week (Monday, Tuesday, ...) will have exactly one numbered day ending with "teen" each month.
+
+If asked to find the teenth Saturday of August, 1953 (or, alternately the "Saturteenth" of August, 1953), we need to look at the calendar for August 1953:
+
+```plaintext
+    August 1953
+Su Mo Tu We Th Fr Sa
+                   1
+ 2  3  4  5  6  7  8
+ 9 10 11 12 13 14 15
+16 17 18 19 20 21 22
+23 24 25 26 27 28 29
+30 31
+```
+
+The Saturday that has a number ending in '-teen' is August 15, 1953.
diff --git a/exercises/practice/nth-prime/.meta/config.json b/exercises/practice/nth-prime/.meta/config.json
index be48887f9..639296a10 100644
--- a/exercises/practice/nth-prime/.meta/config.json
+++ b/exercises/practice/nth-prime/.meta/config.json
@@ -27,5 +27,5 @@
   },
   "blurb": "Given a number n, determine what the nth prime is.",
   "source": "A variation on Problem 7 at Project Euler",
-  "source_url": "http://projecteuler.net/problem=7"
+  "source_url": "https://projecteuler.net/problem=7"
 }
diff --git a/exercises/practice/nucleotide-count/.meta/config.json b/exercises/practice/nucleotide-count/.meta/config.json
index 3b59d523d..f5f108785 100644
--- a/exercises/practice/nucleotide-count/.meta/config.json
+++ b/exercises/practice/nucleotide-count/.meta/config.json
@@ -27,5 +27,5 @@
   },
   "blurb": "Given a DNA string, compute how many times each nucleotide occurs in the string.",
   "source": "The Calculating DNA Nucleotides_problem at Rosalind",
-  "source_url": "http://rosalind.info/problems/dna/"
+  "source_url": "https://rosalind.info/problems/dna/"
 }
diff --git a/exercises/practice/palindrome-products/.meta/config.json b/exercises/practice/palindrome-products/.meta/config.json
index 3d0c7fe54..961b98edf 100644
--- a/exercises/practice/palindrome-products/.meta/config.json
+++ b/exercises/practice/palindrome-products/.meta/config.json
@@ -27,5 +27,5 @@
   },
   "blurb": "Detect palindrome products in a given range.",
   "source": "Problem 4 at Project Euler",
-  "source_url": "http://projecteuler.net/problem=4"
+  "source_url": "https://projecteuler.net/problem=4"
 }
diff --git a/exercises/practice/pangram/.docs/instructions.md b/exercises/practice/pangram/.docs/instructions.md
index d5698bc2a..817c872d9 100644
--- a/exercises/practice/pangram/.docs/instructions.md
+++ b/exercises/practice/pangram/.docs/instructions.md
@@ -5,4 +5,4 @@ Your task is to figure out if a sentence is a pangram.
 A pangram is a sentence using every letter of the alphabet at least once.
 It is case insensitive, so it doesn't matter if a letter is lower-case (e.g. `k`) or upper-case (e.g. `K`).
 
-For this exercise we only use the basic letters used in the English alphabet: `a` to `z`.
+For this exercise, a sentence is a pangram if it contains each of the 26 letters in the English alphabet.
diff --git a/exercises/practice/pangram/.docs/introduction.md b/exercises/practice/pangram/.docs/introduction.md
index d38fa341d..32b6f1fc3 100644
--- a/exercises/practice/pangram/.docs/introduction.md
+++ b/exercises/practice/pangram/.docs/introduction.md
@@ -7,10 +7,10 @@ To give a comprehensive sense of the font, the random sentences should use **all
 They're running a competition to get suggestions for sentences that they can use.
 You're in charge of checking the submissions to see if they are valid.
 
-```exercism/note
+~~~~exercism/note
 Pangram comes from Greek, παν γράμμα, pan gramma, which means "every letter".
 
 The best known English pangram is:
 
 > The quick brown fox jumps over the lazy dog.
-```
+~~~~
diff --git a/exercises/practice/pascals-triangle/.meta/config.json b/exercises/practice/pascals-triangle/.meta/config.json
index d08439ecd..7477bbeae 100644
--- a/exercises/practice/pascals-triangle/.meta/config.json
+++ b/exercises/practice/pascals-triangle/.meta/config.json
@@ -27,5 +27,5 @@
   },
   "blurb": "Compute Pascal's triangle up to a given number of rows.",
   "source": "Pascal's Triangle at Wolfram Math World",
-  "source_url": "http://mathworld.wolfram.com/PascalsTriangle.html"
+  "source_url": "https://www.wolframalpha.com/input/?i=Pascal%27s+triangle"
 }
diff --git a/exercises/practice/perfect-numbers/.meta/config.json b/exercises/practice/perfect-numbers/.meta/config.json
index 6e32e7aff..14587acb7 100644
--- a/exercises/practice/perfect-numbers/.meta/config.json
+++ b/exercises/practice/perfect-numbers/.meta/config.json
@@ -26,5 +26,5 @@
   },
   "blurb": "Determine if a number is perfect, abundant, or deficient based on Nicomachus' (60 - 120 CE) classification scheme for positive integers.",
   "source": "Taken from Chapter 2 of Functional Thinking by Neal Ford.",
-  "source_url": "http://shop.oreilly.com/product/0636920029687.do"
+  "source_url": "https://www.oreilly.com/library/view/functional-thinking/9781449365509/"
 }
diff --git a/exercises/practice/phone-number/.meta/config.json b/exercises/practice/phone-number/.meta/config.json
index b48c69b54..eb68c62ee 100644
--- a/exercises/practice/phone-number/.meta/config.json
+++ b/exercises/practice/phone-number/.meta/config.json
@@ -27,6 +27,6 @@
     ]
   },
   "blurb": "Clean up user-entered phone numbers so that they can be sent SMS messages.",
-  "source": "Event Manager by JumpstartLab",
-  "source_url": "http://tutorials.jumpstartlab.com/projects/eventmanager.html"
+  "source": "Exercise by the JumpstartLab team for students at The Turing School of Software and Design.",
+  "source_url": "https://turing.edu"
 }
diff --git a/exercises/practice/pig-latin/.docs/instructions.md b/exercises/practice/pig-latin/.docs/instructions.md
index 30e646bce..032905aa9 100644
--- a/exercises/practice/pig-latin/.docs/instructions.md
+++ b/exercises/practice/pig-latin/.docs/instructions.md
@@ -8,12 +8,13 @@ It obeys a few simple rules (below), but when it's spoken quickly it's really di
 - **Rule 1**: If a word begins with a vowel sound, add an "ay" sound to the end of the word.
   Please note that "xr" and "yt" at the beginning of a word make vowel sounds (e.g. "xray" -> "xrayay", "yttria" -> "yttriaay").
 - **Rule 2**: If a word begins with a consonant sound, move it to the end of the word and then add an "ay" sound to the end of the word.
-  Consonant sounds can be made up of multiple consonants, a.k.a. a consonant cluster (e.g. "chair" -> "airchay").
+  Consonant sounds can be made up of multiple consonants, such as the "ch" in "chair" or "st" in "stand" (e.g. "chair" -> "airchay").
 - **Rule 3**: If a word starts with a consonant sound followed by "qu", move it to the end of the word, and then add an "ay" sound to the end of the word (e.g. "square" -> "aresquay").
 - **Rule 4**: If a word contains a "y" after a consonant cluster or as the second letter in a two letter word it makes a vowel sound (e.g. "rhythm" -> "ythmrhay", "my" -> "ymay").
 
 There are a few more rules for edge cases, and there are regional variants too.
+Check the tests for all the details.
 
 Read more about [Pig Latin on Wikipedia][pig-latin].
 
-[pig-latin]: http://en.wikipedia.org/wiki/Pig_latin
+[pig-latin]: https://en.wikipedia.org/wiki/Pig_latin
diff --git a/exercises/practice/prime-factors/.meta/config.json b/exercises/practice/prime-factors/.meta/config.json
index 99bcc2ec2..56fdaf266 100644
--- a/exercises/practice/prime-factors/.meta/config.json
+++ b/exercises/practice/prime-factors/.meta/config.json
@@ -24,5 +24,5 @@
   },
   "blurb": "Compute the prime factors of a given natural number.",
   "source": "The Prime Factors Kata by Uncle Bob",
-  "source_url": "http://butunclebob.com/ArticleS.UncleBob.ThePrimeFactorsKata"
+  "source_url": "https://web.archive.org/web/20221026171801/http://butunclebob.com/ArticleS.UncleBob.ThePrimeFactorsKata"
 }
diff --git a/exercises/practice/pythagorean-triplet/.meta/config.json b/exercises/practice/pythagorean-triplet/.meta/config.json
index 395475877..7f64bd295 100644
--- a/exercises/practice/pythagorean-triplet/.meta/config.json
+++ b/exercises/practice/pythagorean-triplet/.meta/config.json
@@ -20,5 +20,5 @@
   },
   "blurb": "There exists exactly one Pythagorean triplet for which a + b + c = 1000. Find the product a * b * c.",
   "source": "Problem 9 at Project Euler",
-  "source_url": "http://projecteuler.net/problem=9"
+  "source_url": "https://projecteuler.net/problem=9"
 }
diff --git a/exercises/practice/queen-attack/.docs/instructions.md b/exercises/practice/queen-attack/.docs/instructions.md
index dce0fc298..ad7ea9547 100644
--- a/exercises/practice/queen-attack/.docs/instructions.md
+++ b/exercises/practice/queen-attack/.docs/instructions.md
@@ -21,5 +21,5 @@ So if you are told the white queen is at `c5` (zero-indexed at column 2, row 3)
   a b c d e f g h
 ```
 
-You are also be able to answer whether the queens can attack each other.
+You are also able to answer whether the queens can attack each other.
 In this case, that answer would be yes, they can, because both pieces share a diagonal.
diff --git a/exercises/practice/queen-attack/.meta/config.json b/exercises/practice/queen-attack/.meta/config.json
index b98c7ba9c..27658c3e3 100644
--- a/exercises/practice/queen-attack/.meta/config.json
+++ b/exercises/practice/queen-attack/.meta/config.json
@@ -24,5 +24,5 @@
   },
   "blurb": "Given the position of two queens on a chess board, indicate whether or not they are positioned so that they can attack each other.",
   "source": "J Dalbey's Programming Practice problems",
-  "source_url": "http://users.csc.calpoly.edu/~jdalbey/103/Projects/ProgrammingPractice.html"
+  "source_url": "https://users.csc.calpoly.edu/~jdalbey/103/Projects/ProgrammingPractice.html"
 }
diff --git a/exercises/practice/resistor-color-duo/.docs/instructions.md b/exercises/practice/resistor-color-duo/.docs/instructions.md
index 68550f780..bdcd549b1 100644
--- a/exercises/practice/resistor-color-duo/.docs/instructions.md
+++ b/exercises/practice/resistor-color-duo/.docs/instructions.md
@@ -3,8 +3,8 @@
 If you want to build something using a Raspberry Pi, you'll probably use _resistors_.
 For this exercise, you need to know two things about them:
 
-* Each resistor has a resistance value.
-* Resistors are small - so small in fact that if you printed the resistance value on them, it would be hard to read.
+- Each resistor has a resistance value.
+- Resistors are small - so small in fact that if you printed the resistance value on them, it would be hard to read.
 
 To get around this problem, manufacturers print color-coded bands onto the resistors to denote their resistance values.
 Each band has a position and a numeric value.
@@ -17,16 +17,16 @@ The program will take color names as input and output a two digit number, even i
 
 The band colors are encoded as follows:
 
-* Black: 0
-* Brown: 1
-* Red: 2
-* Orange: 3
-* Yellow: 4
-* Green: 5
-* Blue: 6
-* Violet: 7
-* Grey: 8
-* White: 9
+- Black: 0
+- Brown: 1
+- Red: 2
+- Orange: 3
+- Yellow: 4
+- Green: 5
+- Blue: 6
+- Violet: 7
+- Grey: 8
+- White: 9
 
 From the example above:
 brown-green should return 15
diff --git a/exercises/practice/resistor-color-trio/.docs/instructions.md b/exercises/practice/resistor-color-trio/.docs/instructions.md
index fcc76958a..59d22783b 100644
--- a/exercises/practice/resistor-color-trio/.docs/instructions.md
+++ b/exercises/practice/resistor-color-trio/.docs/instructions.md
@@ -23,7 +23,7 @@ For this exercise, you need to know only three things about them:
 - Grey: 8
 - White: 9
 
-In `resistor-color duo` you decoded the first two colors.
+In Resistor Color Duo you decoded the first two colors.
 For instance: orange-orange got the main value `33`.
 The third color stands for how many zeros need to be added to the main value.
 The main value plus the zeros gives us a value in ohms.
@@ -46,9 +46,11 @@ So an input of `"orange", "orange", "black"` should return:
 
 > "33 ohms"
 
-When we get more than a thousand ohms, we say "kiloohms".
-That's similar to saying "kilometer" for 1000 meters, and "kilograms" for 1000 grams.
+When we get to larger resistors, a [metric prefix][metric-prefix] is used to indicate a larger magnitude of ohms, such as "kiloohms".
+That is similar to saying "2 kilometers" instead of "2000 meters", or "2 kilograms" for "2000 grams".
 
-So an input of `"orange", "orange", "orange"` should return:
+For example, an input of `"orange", "orange", "orange"` should return:
 
 > "33 kiloohms"
+
+[metric-prefix]: https://en.wikipedia.org/wiki/Metric_prefix
diff --git a/exercises/practice/rna-transcription/.meta/config.json b/exercises/practice/rna-transcription/.meta/config.json
index c11978f46..c40ecf39d 100644
--- a/exercises/practice/rna-transcription/.meta/config.json
+++ b/exercises/practice/rna-transcription/.meta/config.json
@@ -27,5 +27,5 @@
   },
   "blurb": "Given a DNA strand, return its RNA Complement Transcription.",
   "source": "Hyperphysics",
-  "source_url": "http://hyperphysics.phy-astr.gsu.edu/hbase/Organic/transcription.html"
+  "source_url": "https://web.archive.org/web/20220408112140/http://hyperphysics.phy-astr.gsu.edu/hbase/Organic/transcription.html"
 }
diff --git a/exercises/practice/roman-numerals/.docs/instructions.md b/exercises/practice/roman-numerals/.docs/instructions.md
index bb7e909db..247ea0892 100644
--- a/exercises/practice/roman-numerals/.docs/instructions.md
+++ b/exercises/practice/roman-numerals/.docs/instructions.md
@@ -36,6 +36,6 @@ In Roman numerals 1990 is MCMXC:
 2000=MM
 8=VIII
 
-Learn more about [Roman numberals on Wikipedia][roman-numerals].
+Learn more about [Roman numerals on Wikipedia][roman-numerals].
 
 [roman-numerals]: https://wiki.imperivm-romanvm.com/wiki/Roman_Numerals
diff --git a/exercises/practice/roman-numerals/.meta/config.json b/exercises/practice/roman-numerals/.meta/config.json
index 98f5a5322..30c7cd75f 100644
--- a/exercises/practice/roman-numerals/.meta/config.json
+++ b/exercises/practice/roman-numerals/.meta/config.json
@@ -28,5 +28,5 @@
   },
   "blurb": "Write a function to convert from normal numbers to Roman Numerals.",
   "source": "The Roman Numeral Kata",
-  "source_url": "http://codingdojo.org/cgi-bin/index.pl?KataRomanNumerals"
+  "source_url": "https://codingdojo.org/kata/RomanNumerals/"
 }
diff --git a/exercises/practice/say/.docs/instructions.md b/exercises/practice/say/.docs/instructions.md
index aa2e7687f..fb4a6dfb9 100644
--- a/exercises/practice/say/.docs/instructions.md
+++ b/exercises/practice/say/.docs/instructions.md
@@ -48,13 +48,3 @@ Put it all together to get nothing but plain English.
 `12345` should give `twelve thousand three hundred forty-five`.
 
 The program must also report any values that are out of range.
-
-### Extensions
-
-Use _and_ (correctly) when spelling out the number in English:
-
-- 14 becomes "fourteen".
-- 100 becomes "one hundred".
-- 120 becomes "one hundred and twenty".
-- 1002 becomes "one thousand and two".
-- 1323 becomes "one thousand three hundred and twenty-three".
diff --git a/exercises/practice/say/.meta/config.json b/exercises/practice/say/.meta/config.json
index 6ff391788..ca999862c 100644
--- a/exercises/practice/say/.meta/config.json
+++ b/exercises/practice/say/.meta/config.json
@@ -24,6 +24,6 @@
     ]
   },
   "blurb": "Given a number from 0 to 999,999,999,999, spell out that number in English.",
-  "source": "A variation on JavaRanch CattleDrive, exercise 4a",
-  "source_url": "http://www.javaranch.com/say.jsp"
+  "source": "A variation on the JavaRanch CattleDrive, Assignment 4",
+  "source_url": "https://coderanch.com/wiki/718804"
 }
diff --git a/exercises/practice/secret-handshake/.docs/instructions.md b/exercises/practice/secret-handshake/.docs/instructions.md
index 77136cf0f..d2120b9bf 100644
--- a/exercises/practice/secret-handshake/.docs/instructions.md
+++ b/exercises/practice/secret-handshake/.docs/instructions.md
@@ -43,5 +43,6 @@ jump, double blink
 
 ~~~~exercism/note
 If you aren't sure what binary is or how it works, check out [this binary tutorial][intro-to-binary].
+
 [intro-to-binary]: https://medium.com/basecs/bits-bytes-building-with-binary-13cb4289aafa
 ~~~~
diff --git a/exercises/practice/secret-handshake/.meta/config.json b/exercises/practice/secret-handshake/.meta/config.json
index 6cc388bc7..685e22d67 100644
--- a/exercises/practice/secret-handshake/.meta/config.json
+++ b/exercises/practice/secret-handshake/.meta/config.json
@@ -24,5 +24,5 @@
   },
   "blurb": "Given a decimal number, convert it to the appropriate sequence of events for a secret handshake.",
   "source": "Bert, in Mary Poppins",
-  "source_url": "http://www.imdb.com/title/tt0058331/quotes/qt0437047"
+  "source_url": "https://www.imdb.com/title/tt0058331/quotes/?item=qt0437047"
 }
diff --git a/exercises/practice/series/.meta/config.json b/exercises/practice/series/.meta/config.json
index 0c6ae38a3..b64a48f65 100644
--- a/exercises/practice/series/.meta/config.json
+++ b/exercises/practice/series/.meta/config.json
@@ -27,5 +27,5 @@
   },
   "blurb": "Given a string of digits, output all the contiguous substrings of length `n` in that string.",
   "source": "A subset of the Problem 8 at Project Euler",
-  "source_url": "http://projecteuler.net/problem=8"
+  "source_url": "https://projecteuler.net/problem=8"
 }
diff --git a/exercises/practice/sieve/.docs/instructions.md b/exercises/practice/sieve/.docs/instructions.md
index c3c0abeb8..3adf1d551 100644
--- a/exercises/practice/sieve/.docs/instructions.md
+++ b/exercises/practice/sieve/.docs/instructions.md
@@ -1,28 +1,28 @@
 # Instructions
 
-Use the Sieve of Eratosthenes to find all the primes from 2 up to a given
-number.
+Your task is to create a program that implements the Sieve of Eratosthenes algorithm to find prime numbers.
 
-The Sieve of Eratosthenes is a simple, ancient algorithm for finding all prime numbers up to any given limit.
-It does so by iteratively marking as composite (i.e. not prime) the multiples of each prime, starting with the multiples of 2.
-It does not use any division or remainder operation.
+A prime number is a number that is only divisible by 1 and itself.
+For example, 2, 3, 5, 7, 11, and 13 are prime numbers.
 
-Create your range, starting at two and continuing up to and including the given limit.
-(i.e. [2, limit])
+The Sieve of Eratosthenes is an ancient algorithm that works by taking a list of numbers and crossing out all the numbers that aren't prime.
 
-The algorithm consists of repeating the following over and over:
+A number that is **not** prime is called a "composite number".
 
-- take the next available unmarked number in your list (it is prime)
-- mark all the multiples of that number (they are not prime)
+To use the Sieve of Eratosthenes, you first create a list of all the numbers between 2 and your given number.
+Then you repeat the following steps:
 
-Repeat until you have processed each number in your range.
+1. Find the next unmarked number in your list. This is a prime number.
+2. Mark all the multiples of that prime number as composite (not prime).
 
-When the algorithm terminates, all the numbers in the list that have not
-been marked are prime.
+You keep repeating these steps until you've gone through every number in your list.
+At the end, all the unmarked numbers are prime.
 
-[This wikipedia article][eratosthenes] has a useful graphic that explains the algorithm.
+~~~~exercism/note
+[Wikipedia's Sieve of Eratosthenes article][eratosthenes] has a useful graphic that explains the algorithm.
 
-Notice that this is a very specific algorithm, and the tests don't check that you've implemented the algorithm, only that you've come up with the correct list of primes.
-A good first test is to check that you do not use division or remainder operations (div, /, mod or % depending on the language).
+The tests don't check that you've implemented the algorithm, only that you've come up with the correct list of primes.
+A good first test is to check that you do not use division or remainder operations.
 
 [eratosthenes]: https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
+~~~~
diff --git a/exercises/practice/sieve/.docs/introduction.md b/exercises/practice/sieve/.docs/introduction.md
new file mode 100644
index 000000000..f6c1cf79a
--- /dev/null
+++ b/exercises/practice/sieve/.docs/introduction.md
@@ -0,0 +1,7 @@
+# Introduction
+
+You bought a big box of random computer parts at a garage sale.
+You've started putting the parts together to build custom computers.
+
+You want to test the performance of different combinations of parts, and decide to create your own benchmarking program to see how your computers compare.
+You choose the famous "Sieve of Eratosthenes" algorithm, an ancient algorithm, but one that should push your computers to the limits.
diff --git a/exercises/practice/sieve/.meta/config.json b/exercises/practice/sieve/.meta/config.json
index f8eb8a016..47577b410 100644
--- a/exercises/practice/sieve/.meta/config.json
+++ b/exercises/practice/sieve/.meta/config.json
@@ -28,5 +28,5 @@
   },
   "blurb": "Use the Sieve of Eratosthenes to find all the primes from 2 up to a given number.",
   "source": "Sieve of Eratosthenes at Wikipedia",
-  "source_url": "http://en.wikipedia.org/wiki/Sieve_of_Eratosthenes"
+  "source_url": "https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes"
 }
diff --git a/exercises/practice/space-age/.docs/instructions.md b/exercises/practice/space-age/.docs/instructions.md
index bbe5a702e..fe938cc09 100644
--- a/exercises/practice/space-age/.docs/instructions.md
+++ b/exercises/practice/space-age/.docs/instructions.md
@@ -16,4 +16,10 @@ be able to say that they're 31.69 Earth-years old.
 
 If you're wondering why Pluto didn't make the cut, go watch [this YouTube video][pluto-video].
 
-[pluto-video]: http://www.youtube.com/watch?v=Z_2gbGXzFbs
+Note: The actual length of one complete orbit of the Earth around the sun is closer to 365.256 days (1 sidereal year).
+The Gregorian calendar has, on average, 365.2425 days.
+While not entirely accurate, 365.25 is the value used in this exercise.
+See [Year on Wikipedia][year] for more ways to measure a year.
+
+[pluto-video]: https://www.youtube.com/watch?v=Z_2gbGXzFbs
+[year]: https://en.wikipedia.org/wiki/Year#Summary
diff --git a/exercises/practice/space-age/.meta/config.json b/exercises/practice/space-age/.meta/config.json
index 5a0a321d2..22ce6318c 100644
--- a/exercises/practice/space-age/.meta/config.json
+++ b/exercises/practice/space-age/.meta/config.json
@@ -26,5 +26,5 @@
   },
   "blurb": "Given an age in seconds, calculate how old someone is in terms of a given planet's solar years.",
   "source": "Partially inspired by Chapter 1 in Chris Pine's online Learn to Program tutorial.",
-  "source_url": "http://pine.fm/LearnToProgram/?Chapter=01"
+  "source_url": "https://pine.fm/LearnToProgram/?Chapter=01"
 }
diff --git a/exercises/practice/triangle/.meta/config.json b/exercises/practice/triangle/.meta/config.json
index 12c18a0fe..d670d173c 100644
--- a/exercises/practice/triangle/.meta/config.json
+++ b/exercises/practice/triangle/.meta/config.json
@@ -26,5 +26,5 @@
   },
   "blurb": "Determine if a triangle is equilateral, isosceles, or scalene.",
   "source": "The Ruby Koans triangle project, parts 1 & 2",
-  "source_url": "http://rubykoans.com"
+  "source_url": "https://web.archive.org/web/20220831105330/http://rubykoans.com"
 }
diff --git a/exercises/practice/two-bucket/.meta/config.json b/exercises/practice/two-bucket/.meta/config.json
index c3c5be62d..f1a863785 100644
--- a/exercises/practice/two-bucket/.meta/config.json
+++ b/exercises/practice/two-bucket/.meta/config.json
@@ -20,5 +20,5 @@
   },
   "blurb": "Given two buckets of different size, demonstrate how to measure an exact number of liters.",
   "source": "Water Pouring Problem",
-  "source_url": "http://demonstrations.wolfram.com/WaterPouringProblem/"
+  "source_url": "https://demonstrations.wolfram.com/WaterPouringProblem/"
 }
diff --git a/exercises/practice/two-fer/.docs/instructions.md b/exercises/practice/two-fer/.docs/instructions.md
index a9bb4a3cd..37aa75297 100644
--- a/exercises/practice/two-fer/.docs/instructions.md
+++ b/exercises/practice/two-fer/.docs/instructions.md
@@ -17,9 +17,9 @@ One for you, one for me.
 
 Here are some examples:
 
-|Name    |Dialogue
-|:-------|:------------------
-|Alice   |One for Alice, one for me.
-|Bohdan  |One for Bohdan, one for me.
-|        |One for you, one for me.
-|Zaphod  |One for Zaphod, one for me.
+| Name   | Dialogue                    |
+| :----- | :-------------------------- |
+| Alice  | One for Alice, one for me.  |
+| Bohdan | One for Bohdan, one for me. |
+|        | One for you, one for me.    |
+| Zaphod | One for Zaphod, one for me. |
diff --git a/exercises/practice/wordy/.docs/instructions.md b/exercises/practice/wordy/.docs/instructions.md
index 59cb4561b..0b9e67b6c 100644
--- a/exercises/practice/wordy/.docs/instructions.md
+++ b/exercises/practice/wordy/.docs/instructions.md
@@ -54,6 +54,6 @@ Since these are verbal word problems, evaluate the expression from left-to-right
 
 The parser should reject:
 
-* Unsupported operations ("What is 52 cubed?")
-* Non-math questions ("Who is the President of the United States")
-* Word problems with invalid syntax ("What is 1 plus plus 2?")
+- Unsupported operations ("What is 52 cubed?")
+- Non-math questions ("Who is the President of the United States")
+- Word problems with invalid syntax ("What is 1 plus plus 2?")