diff --git a/docs/difference-from-coleslaw.lisp b/docs/difference-from-coleslaw.lisp
index 68788df..888c098 100644
--- a/docs/difference-from-coleslaw.lisp
+++ b/docs/difference-from-coleslaw.lisp
@@ -3,18 +3,32 @@
   "
 Staticl config is constructed from lisp function calls and you can benefit from IDE's code completion.
 
-Variable `config` was renamed to `site`.
-    post -> content
-    pubdate -> site.pubdate.
-    site.sitenav -> site.navigation.items also for items inside navigation now have a \"title\" slot instead of \"name\" and also navigation menu can contain submenus, but this requires a special support from the theme. If an item has slot \"item\", then it is a submenu.
+The first important variable `config` was renamed to `site`. Secondly, variables `post` and `index` were renamed to `content`. That is it - content of any page, be it a post or a generic page is available as `content` variable inside the template.
 
-    index -> content
-    index.content -> content.items
-    prev -> content.prev
-    next -> content.next
-    tags -> content.tags
-    obj.date -> obj.created_at
+## Changes in navigation
 
+The `site.sitenav` list was renamed to `site.navigation.items`. Also items inside the navigation now have a `title` slot instead of `name` and also navigation menu can contain submenus, but this requires a special support from the theme. If an item has a slot `item`, then it is a submenu. Themes ported from the Coleslaw do not support this submenues.
+
+## Index pages
+
+For index pages a list of items was also moved and now instead of `index.content` a `content.items` should be used.
+
+### Index objects
+
+For objects in `content.items` attribute `obj.text` was renamed to `obj.excerpt`. It is a HTML, so `noAutoescape` filter should be applied (as you did in Coleslaw themes too).
+
+## Other field renames
+
+- `pubdate -> site.pubdate`
+- `obj.date -> obj.created_at`
+- `post.date -> content.created_at`
+- `post.text -> content.html`
+- `tags -> content.tags`
+- `prev -> content.prev`
+- `next -> content.next`
+
+
+## Working with dates
 
 For templates base on Closure Template, StatiCL defines these filters:
 
@@ -23,15 +37,20 @@ For templates base on Closure Template, StatiCL defines these filters:
 
 To define additional filters, inherit your template class from CLOSURE-TEMPLATE and define a method for REGISTER-USER-FILTERS generic-function.
 
-Instead of makin 1.html and symlinking to it from index.html, StatiCL just generates first page as index.html and other pages as 2.html, 3.html, etc.
-
-
-URLs
+## URLs
 
 Templates in Coleslaw used {$site.domain}/ as a prefix to each URL. With StatiCL all URLs are formatted in advance before
 variables are passed to the template and you don't have to concatenate string to get a proper URL in a template.
 
-Additional formats
+Also, note, that instead of making 1.html and symlinking to it from index.html for post indices, StatiCL just generates first page as index.html and other pages as 2.html, 3.html, etc..
+
+
+## Pages layout
+
+Coleslaw uses a subfolder `pages/` to keep content of all site pages and put them to the root of the site. Staticl does not implement this logic - it generates an output page with the same path as an original file. For example, if previousl with Coleslaw you put `/pages/about.post` to get `/about.html` page, with Staticl you write `/about.post` source file to generate `/about.html` or `/about/index.html` (depending on clean urls setting).
+
+
+## Additional formats
 
 * (ql:quickload :staticl/format/spinneret)
 
diff --git a/example/.staticlrc b/example/.staticlrc
index a778559..29be7d2 100644
--- a/example/.staticlrc
+++ b/example/.staticlrc
@@ -9,7 +9,7 @@
       :url "https://example.com/"
       :navigation (menu (item "Blog (EN)" "/blog/")
                         (item "Blog (RU)" "/ru/blog/")
-                        (item "About" "/about.html"))
+                        (item "About" "/about/"))
       :pipeline (list (load-content)
                       (filter (:path "ru/")
                               (prev-next-links)
diff --git a/example/ru/index.post b/example/ru/index.page
similarity index 100%
rename from example/ru/index.post
rename to example/ru/index.page
diff --git a/qlfile.lock b/qlfile.lock
index 0aa8290..890c2fb 100644
--- a/qlfile.lock
+++ b/qlfile.lock
@@ -1,11 +1,11 @@
 ("quicklisp" .
  (:class qlot/source/dist:source-dist
-  :initargs (:distribution "http://beta.quicklisp.org/dist/quicklisp.txt" :%version :latest)
+  :initargs (:distribution "https://beta.quicklisp.org/dist/quicklisp.txt" :%version :latest)
   :version "2023-10-21"))
 ("ultralisp" .
  (:class qlot/source/dist:source-dist
-  :initargs (:distribution "http://dist.ultralisp.org/" :%version :latest)
-  :version "20240330015000"))
+  :initargs (:distribution "https://dist.ultralisp.org/" :%version :latest)
+  :version "20240428124000"))
 ("slynk" .
  (:class qlot/source/github:source-github
   :initargs (:repos "svetlyak40wt/sly" :ref nil :branch "patches" :tag nil)
diff --git a/src/clean-urls.lisp b/src/clean-urls.lisp
new file mode 100644
index 0000000..015fbce
--- /dev/null
+++ b/src/clean-urls.lisp
@@ -0,0 +1,73 @@
+(uiop:define-package #:staticl/clean-urls
+  (:use #:cl)
+  (:import-from #:staticl/site
+                #:clean-urls-p
+                #:site)
+  (:import-from #:str
+                #:ends-with-p)
+  (:import-from #:serapeum
+                #:->)
+  (:export #:transform-url
+           #:transform-filename))
+(in-package #:staticl/clean-urls)
+
+
+(-> clean-url (string)
+    (values string &optional))
+
+(defun clean-url (url)
+  (cond
+    ((ends-with-p "/index.html" url)
+     (subseq url 0 (1+ (- (length url)
+                          (length "/index.html")))))
+    ((ends-with-p ".html" url)
+     (concatenate 'string
+                  (subseq url 0 (- (length url)
+                                   (length ".html")))
+                  "/"))
+    (t
+     url)))
+
+
+(-> clean-pathname (pathname)
+    (values pathname &optional))
+
+(defun clean-pathname (filename)
+  (cond
+    ((and (string-equal (pathname-type filename)
+                    "html")
+          (not (string-equal (pathname-name filename)
+                             "index")))
+     (merge-pathnames
+      (make-pathname :directory (list :relative (pathname-name filename))
+                     :name "index"
+                     :type "html")
+      filename))
+    (t
+     filename)))
+
+
+(defgeneric transform-url (site url)
+  (:documentation "Converts the URL to the form that should be used on the site.
+
+                   If the site has the clean-urls setting enabled, then the URL like /some/page.html will be converted
+                   to /some/page/. If clean-urls is not enabled, the URL will remain unchanged.")
+  (:method ((site site) (url string))
+    (cond
+      ((clean-urls-p site)
+       (clean-url url))
+      (t
+       url))))
+
+
+(defgeneric transform-filename (site filename)
+  (:documentation "Converts the pathname to the form that should be used to write content to the disk.
+
+                   If the site has the clean-urls setting enabled, then the filename like some/page.html will be converted
+                   to some/page/index.html. If clean-urls is not enabled, the pathname will remain unchanged.")
+  (:method ((site site) (filename pathname))
+    (cond
+      ((and (clean-urls-p site))
+       (clean-pathname filename))
+      (t
+       filename))))
diff --git a/src/content.lisp b/src/content.lisp
index f61fe8e..a9035ed 100644
--- a/src/content.lisp
+++ b/src/content.lisp
@@ -1,7 +1,5 @@
 (uiop:define-package #:staticl/content
   (:use #:cl)
-  (:import-from #:staticl/theme
-                #:template-vars)
   (:import-from #:serapeum
                 #:->
                 #:dict)
@@ -13,6 +11,7 @@
                 #:site-content-root
                 #:site)
   (:import-from #:alexandria
+                #:curry
                 #:with-output-to-file
                 #:length=)
   (:import-from #:staticl/utils
@@ -45,6 +44,8 @@
   (:import-from #:staticl/content/html-content
                 #:content-html-excerpt
                 #:content-html)
+  (:import-from #:staticl/clean-urls
+                #:transform-filename)
   (:export #:supported-content-types
            #:content-type
            #:content
@@ -249,10 +250,14 @@
       (merge-pathnames
        (merge-pathnames (make-pathname :type "html")
                         relative-path)
-       stage-dir))))
+       stage-dir)))
+  
+  (:method :around ((site site) (content content) (stage-dir pathname))
+    (transform-filename site
+                        (call-next-method))))
 
 
-(defmethod object-url ((content content-from-file) &key &allow-other-keys)
+(defmethod object-url ((site site) (content content-from-file) &key &allow-other-keys)
   (or (slot-value content 'url)
       (let* ((root (current-root))
              (relative-path (enough-namestring (content-file content)
@@ -267,8 +272,8 @@
 
   (:method ((site site) (content content) (stream stream))
     (let* ((theme (site-theme site))
-           (content-vars (template-vars content))
-           (site-vars (template-vars site))
+           (content-vars (template-vars site content))
+           (site-vars (template-vars site site))
            (vars (dict "site" site-vars
                        "content" content-vars))
            (template-name (content-template content)))
@@ -280,9 +285,9 @@
   (:documentation "Returns an additional list content objects such as RSS feeds or sitemaps."))
 
 
-(defmethod template-vars :around ((content content) &key (hash (dict)))
+(defmethod template-vars :around ((site site) (content content) &key (hash (dict)))
   (loop with result = (if (next-method-p)
-                          (call-next-method content :hash hash)
+                          (call-next-method site content :hash hash)
                           (values hash))
         for key being the hash-key of (content-metadata content)
           using (hash-value value)
@@ -295,7 +300,7 @@
                    ;; Here we need transform CLOS objects to hash-tables
                    ;; to make their fields accessable in the template
                    (standard-object
-                    (template-vars value))
+                    (template-vars site value))
                    ;; Other types are passed as is:
                    (t
                     value)))
@@ -319,7 +324,7 @@
              (content-format content))))
 
 
-(defmethod template-vars ((content content-from-file) &key (hash (dict)))
+(defmethod template-vars ((site site) (content content-from-file) &key (hash (dict)))
   (setf (gethash "title" hash)
         (content-title content)
         (gethash "html" hash)
@@ -343,13 +348,13 @@
         )
   
   (if (next-method-p)
-      (call-next-method content :hash hash)
+      (call-next-method site content :hash hash)
       (values hash)))
 
 
-(defmethod template-vars ((content content-with-tags-mixin) &key (hash (dict)))
+(defmethod template-vars ((site site) (content content-with-tags-mixin) &key (hash (dict)))
   (setf (gethash "tags" hash)
-        (mapcar #'template-vars
+        (mapcar (curry #'template-vars site)
                 (content-tags content)))
   
   (if (next-method-p)
diff --git a/src/core.lisp b/src/core.lisp
index f44be4c..f3f98a2 100644
--- a/src/core.lisp
+++ b/src/core.lisp
@@ -19,7 +19,6 @@
   (:import-from #:staticl/current-root
                 #:with-current-root)
   (:import-from #:staticl/url
-                #:object-url
                 #:with-base-url)
   (:nicknames #:staticl/core)
   (:export #:generate
diff --git a/src/feeds/base.lisp b/src/feeds/base.lisp
index ae31fa4..efaab6a 100644
--- a/src/feeds/base.lisp
+++ b/src/feeds/base.lisp
@@ -74,16 +74,16 @@
 (defmethod staticl/content:write-content-to-stream ((site site) (feed-file feed-file) stream)
   (loop for item in (content-items feed-file)
         for feed-entry = (make-instance 'org.shirakumo.feeder:entry
-                                        :id (staticl/url:object-url item :full t)
-                                        :link (staticl/url:object-url item :full t)
+                                        :id (staticl/url:object-url site item :full t)
+                                        :link (staticl/url:object-url site item :full t)
                                         :title (staticl/content:content-title item)
                                         :summary (staticl/content/html-content:content-html-excerpt item)
                                         :content (staticl/content::content-html item))
         collect feed-entry into entries
         finally
            (let* ((feed (make-instance 'org.shirakumo.feeder:feed
-                                       :id (staticl/url:object-url site :full t)
-                                       :link (staticl/url:object-url site :full t)
+                                       :id (staticl/url:object-url site site :full t)
+                                       :link (staticl/url:object-url site site :full t)
                                        :title (staticl/site:site-title site)
                                        :summary (staticl/site:site-description site)
                                        :content entries))
@@ -92,7 +92,7 @@
              (plump:serialize plump-node stream))))
 
 
-(defmethod object-url ((feed-file feed-file) &key &allow-other-keys)
+(defmethod object-url ((site site) (feed-file feed-file) &key &allow-other-keys)
   (let* ((root (current-root))
          (relative-path (enough-namestring (target-path feed-file)
                                            root)))
diff --git a/src/index/base.lisp b/src/index/base.lisp
index 6f205e5..5abdb4b 100644
--- a/src/index/base.lisp
+++ b/src/index/base.lisp
@@ -90,10 +90,10 @@
 
 
 
-(defmethod template-vars ((content index-page) &key (hash (dict)))
+(defmethod template-vars ((site site) (content index-page) &key (hash (dict)))
   (flet ((item-vars (item)
            (dict "url"
-                 (staticl/url:object-url item)
+                 (staticl/url:object-url site item)
                  "title"
                  (staticl/content:content-title item)
                  "created-at"
@@ -110,19 +110,19 @@
           (when (prev-page content)
             (dict
              "url"
-             (staticl/url:object-url (prev-page content))))
+             (staticl/url:object-url site (prev-page content))))
           (gethash "next" hash)
           (when (next-page content)
             (dict
              "url"
-             (staticl/url:object-url (next-page content))))))
+             (staticl/url:object-url site (next-page content))))))
   
   (if (next-method-p)
       (call-next-method content :hash hash)
       (values hash)))
 
 
-(defmethod object-url ((index index-page) &key &allow-other-keys)
+(defmethod object-url ((site site) (index index-page) &key &allow-other-keys)
   (let* ((root (current-root))
          (relative-path (enough-namestring (page-target-path index)
                                            root)))
diff --git a/src/index/paginated.lisp b/src/index/paginated.lisp
index 76942d7..659ed71 100644
--- a/src/index/paginated.lisp
+++ b/src/index/paginated.lisp
@@ -84,7 +84,10 @@
 
 (defmethod staticl/pipeline:process-items ((site site) (index paginated-index) content-items)
   (loop with only-posts = (remove-if-not #'postp content-items)
-        for batch in (serapeum:batches only-posts (page-size index))
+        with sorted-posts = (sort only-posts
+                                  #'local-time:timestamp>
+                                  :key #'staticl/content:content-created-at )
+        for batch in (serapeum:batches sorted-posts (page-size index))
         for page-number upfrom 1
         collect (make-instance 'index-page
                                :title (funcall (page-title-fn index)
diff --git a/src/links/link.lisp b/src/links/link.lisp
index 146ef44..1969a21 100644
--- a/src/links/link.lisp
+++ b/src/links/link.lisp
@@ -9,6 +9,8 @@
                 #:->)
   (:import-from #:staticl/url
                 #:object-url)
+  (:import-from #:staticl/site
+                #:site)
   (:export
    #:link))
 (in-package #:staticl/links/link)
@@ -32,9 +34,9 @@
                  :content content))
 
 
-(defmethod staticl/theme:template-vars ((link link) &key (hash (dict)))
+(defmethod staticl/theme:template-vars ((site site) (link link) &key (hash (dict)))
   (dict* hash
          "url"
-         (object-url (link-content link))
+         (object-url site (link-content link))
          "title"
          (content-title (link-content link))))
diff --git a/src/plugins/sitemap.lisp b/src/plugins/sitemap.lisp
index 206c1a5..738072c 100644
--- a/src/plugins/sitemap.lisp
+++ b/src/plugins/sitemap.lisp
@@ -48,7 +48,7 @@
 
 (defmethod write-content-to-stream ((site site) (sitemap sitemap-file) (stream stream))
   (render-sitemap (loop for item in (sitemap-content sitemap)
-                        collect (make-url (object-url item :full t)
+                        collect (make-url (object-url site item :full t)
                                           :changefreq :weekly
                                           :priority 0.5))
                   :stream stream))
diff --git a/src/site-url.lisp b/src/site-url.lisp
new file mode 100644
index 0000000..1f20736
--- /dev/null
+++ b/src/site-url.lisp
@@ -0,0 +1,12 @@
+(uiop:define-package #:staticl/site-url
+  (:use #:cl)
+  (:import-from #:staticl/site
+                #:site-url
+                #:site)
+  (:import-from #:staticl/url
+                #:object-url))
+(in-package #:staticl/site-url)
+
+
+(defmethod object-url ((site site) (obj site) &key &allow-other-keys)
+  (site-url obj))
diff --git a/src/site.lisp b/src/site.lisp
index 584da76..0dc25ed 100644
--- a/src/site.lisp
+++ b/src/site.lisp
@@ -20,9 +20,8 @@
                 #:template-vars
                 #:load-theme
                 #:theme)
-  (:import-from #:staticl/url
-                #:assert-absolute-url
-                #:object-url)
+  (:import-from #:staticl/utils
+                #:assert-absolute-url)
   (:import-from #:staticl/current-root
                 #:with-current-root
                 #:current-root)
@@ -35,7 +34,8 @@
            #:site-plugins
            #:site-theme
            #:site-pipeline
-           #:site-description))
+           #:site-description
+           #:clean-urls-p))
 (in-package #:staticl/site)
 
 
@@ -64,6 +64,10 @@
         :type string
         :reader site-url
         :documentation "Site's URL.")
+   (clean-urls :initarg :clean-urls
+               :type boolean
+               :reader clean-urls-p
+               :documentation "Generate some-page/index.html instead of some-page.html to make URLs look like https://my-site.com/some-page/ instead of https://my-site.com/some-page.html")
    (theme :initarg :theme
           :type theme
           :reader site-theme
@@ -78,6 +82,7 @@
    :description (error "DECRIPTION argument is required.")
    :navigation nil
    :url (error "URL argument is required.")
+   :clean-urls t
    :charset "UTF-8"))
 
 
@@ -145,21 +150,19 @@
       (values site))))
 
 
-(defmethod template-vars ((site site) &key (hash (dict)))
+(defmethod template-vars ((site site)
+                          (obj site) &key (hash (dict)))
   (dict* hash 
          "title"
-         (site-title site)
+         (site-title obj)
          "description" 
-         (site-description site)
+         (site-description obj)
          "url" 
-         (site-url site)
+         (site-url obj)
          "pubdate" 
          (local-time:now)
          "charset"
-         (site-charset site)
+         (site-charset obj)
          "navigation"
-         (site-navigation site)))
-
+         (site-navigation obj)))
 
-(defmethod object-url ((site site) &key &allow-other-keys)
-  (site-url site))
diff --git a/src/tag.lisp b/src/tag.lisp
index f4d023e..6ca05a1 100644
--- a/src/tag.lisp
+++ b/src/tag.lisp
@@ -4,6 +4,8 @@
                 #:dict)
   (:import-from #:staticl/theme
                 #:template-vars)
+  (:import-from #:staticl/site
+                #:site)
   (:export #:tag-name
            #:tag))
 (in-package #:staticl/tag)
@@ -17,7 +19,7 @@
    :name (error ":NAME is required argument for a tag.")))
 
 
-(defmethod template-vars ((tag tag) &key (hash (dict)))
+(defmethod template-vars ((site site) (tag tag) &key (hash (dict)))
   (setf (gethash "name" hash)
         (tag-name tag))
   (values hash))
diff --git a/src/theme.lisp b/src/theme.lisp
index cd48cdf..0c38bec 100644
--- a/src/theme.lisp
+++ b/src/theme.lisp
@@ -29,7 +29,7 @@
   (list (list :path "~S" (theme-path theme))))
 
 
-(defgeneric template-vars (object &key hash )
+(defgeneric template-vars (site object &key hash )
   (:documentation "Fills a hash-table given as HASH argument with variables for filling a template.
 
                    If hash is NIL, then a new hash-table should be allocated with EQUAL :TEST argument.
@@ -77,15 +77,20 @@
 (defun load-theme (name &key site-root)
   (let ((builtin-themes-dir
           (asdf:system-relative-pathname "staticl"
-                                         "themes")))
-    (or (when site-root
-          (load-theme-from-dir site-root name))
+                                         "themes"))
+        (site-themes-dir
+          (when site-root
+            (merge-pathnames
+             (make-pathname :directory '(:relative "themes"))
+             (uiop:ensure-directory-pathname site-root)))))
+    (or (when site-themes-dir
+          (load-theme-from-dir site-themes-dir name))
         (load-theme-from-dir builtin-themes-dir
                              name)
         (error "Theme named ~S not found in ~{~A~#[~; and ~:;, ~]~}"
                name
                (remove-if #'null
-                          (list site-root
+                          (list site-themes-dir
                                 builtin-themes-dir))))))
 
 
diff --git a/src/themes/closure-template.lisp b/src/themes/closure-template.lisp
index acfcbe4..36f8229 100644
--- a/src/themes/closure-template.lisp
+++ b/src/themes/closure-template.lisp
@@ -47,12 +47,14 @@
     
     (flet ((format-date (params end value)
              (declare (ignore params end))
-             (format-timestring nil value
-                                :format (date-format theme)))
+             (when value
+               (format-timestring nil value
+                                  :format (date-format theme))))
            (format-datetime (params end value)
              (declare (ignore params end))
-             (format-timestring nil value
-                                :format (datetime-format theme))))
+             (when value
+               (format-timestring nil value
+                                  :format (datetime-format theme)))))
       (register-print-handler :common-lisp-backend
                               'print-date
                               :function #'format-date)
diff --git a/src/url.lisp b/src/url.lisp
index 2662d8b..fc5795b 100644
--- a/src/url.lisp
+++ b/src/url.lisp
@@ -6,17 +6,23 @@
   (:import-from #:alexandria
                 #:with-gensyms
                 #:make-gensym)
+  (:import-from #:staticl/site
+                #:site)
+  (:import-from #:staticl/utils
+                #:assert-absolute-url
+                #:absolute-url-p)
+  (:import-from #:staticl/clean-urls
+                #:transform-url)
   (:export
    #:with-base-url
-   #:object-url
-   #:absolute-url-p))
+   #:object-url))
 (in-package #:staticl/url)
 
 
 (defvar *base-url*)
 
 
-(defgeneric object-url (obj &key full)
+(defgeneric object-url (site obj &key full)
   (:documentation "Returns a full object URL.
                    A method should return an relative URL, but if case if FULL argument was given,
                    the full url with schema and domain will be returned.
@@ -31,7 +37,7 @@
 
                    Actually you will need to use FULL argument only in a rare case when you really need
                    and absolute URL, for example in an RSS feed.")
-  (:method :around ((obj t) &key full)
+  (:method :around ((site site) (obj t) &key full)
     (let* ((result (call-next-method))
            (absolute-url
              (cond
@@ -43,36 +49,13 @@
                          result))
                 (quri:merge-uris result
                                  *base-url*)))))
-      (cond
-        (full
-         (quri:render-uri
-          absolute-url))
-        (t
-         (quri:uri-path absolute-url))))))
-
-
-(-> absolute-url-p (string)
-    (values boolean &optional))
-
-(defun absolute-url-p (url)
-  (let ((parsed (quri:uri url)))
-    (when (and (quri:uri-scheme parsed)
-               (quri:uri-host parsed))
-      (values t))))
-
-
-(-> assert-absolute-url (string)
-    (values string &optional))
-
-(defun assert-absolute-url (url)
-  (let ((parsed (quri:uri url)))
-    (unless (quri:uri-scheme parsed)
-      (error "There is no scheme in ~S."
-             url))
-    (unless (quri:uri-host parsed)
-      (error "There is no host in ~S."
-             url))
-    url))
+      (transform-url site
+                     (cond
+                       (full
+                        (quri:render-uri
+                         absolute-url))
+                       (t
+                        (quri:uri-path absolute-url)))))))
 
 
 (defun call-with-base-url (url thunk)
diff --git a/src/user-package.lisp b/src/user-package.lisp
index a7a53e5..899c7b2 100644
--- a/src/user-package.lisp
+++ b/src/user-package.lisp
@@ -1,14 +1,17 @@
 (uiop:define-package #:staticl-user
   ;; This package does not use all symbols from CL package intentionally:
-  (:use)
+  (:use #:cl)
+  
   (:nicknames #:staticl/user-package)
-  (:import-from #:cl
-                #:list
-                #:t
-                #:nil
-                #:lambda
-                #:let
-                #:in-package)
+  ;; (:import-from #:cl
+  ;;               #:list
+  ;;               #:t
+  ;;               #:nil
+  ;;               #:lambda
+  ;;               #:let
+  ;;               #:in-package
+  ;;               #:defpackage)
+  
   (:import-from #:serapeum
                 #:fmt)
   ;; API imports
@@ -25,8 +28,8 @@
                 #:load-content)
   (:import-from #:staticl/feeds/rss
                 #:rss)
-  (:import-from #:staticl/feeds/atom
-                #:atom)
+  (:shadowing-import-from #:staticl/feeds/atom
+                          #:atom)
   (:import-from #:staticl/filter
                 #:filter)
   (:import-from #:staticl/rsync
diff --git a/src/utils.lisp b/src/utils.lisp
index 97259da..c00353b 100644
--- a/src/utils.lisp
+++ b/src/utils.lisp
@@ -1,6 +1,7 @@
 (uiop:define-package #:staticl/utils
   (:use #:cl)
   (:import-from #:log)
+  (:import-from #:quri)
   (:import-from #:str
                 #:trim-left)
   (:import-from #:serapeum
@@ -14,7 +15,9 @@
                 #:walk-directory)
   (:export
    #:do-files
-   #:normalize-plist))
+   #:normalize-plist
+   #:absolute-url-p
+   #:assert-absolute-url))
 (in-package #:staticl/utils)
 
 
@@ -153,3 +156,27 @@ BODY on files that match the given extension."
     (declare (dynamic-extent #'rec
                              #'to-upper))
     (rec dict)))
+
+
+(-> absolute-url-p (string)
+    (values boolean &optional))
+
+(defun absolute-url-p (url)
+  (let ((parsed (quri:uri url)))
+    (when (and (quri:uri-scheme parsed)
+               (quri:uri-host parsed))
+      (values t))))
+
+
+(-> assert-absolute-url (string)
+    (values string &optional))
+
+(defun assert-absolute-url (url)
+  (let ((parsed (quri:uri url)))
+    (unless (quri:uri-scheme parsed)
+      (error "There is no scheme in ~S."
+             url))
+    (unless (quri:uri-host parsed)
+      (error "There is no host in ~S."
+             url))
+    url))
diff --git a/staticl.asd b/staticl.asd
index 9e27f35..9e1936e 100644
--- a/staticl.asd
+++ b/staticl.asd
@@ -15,7 +15,8 @@
                "staticl/themes/closure-template"
                "staticl/format/html"
                "staticl/format/md"
-               "staticl/user-package")
+               "staticl/user-package"
+               "staticl/site-url")
   :in-order-to ((test-op (test-op "staticl-tests"))))