MagLev is a Ruby implementation than runs on top of the GemStone/S Smalltalk VM. It can transparently manage a large amount (petabytes) of data and has a scalable built-in model for parallelism across VMs. Since all connected VMs see the same objects, it can have thousands of truly parallel processes running in a single, shared, transactional object space.
MagLev isn't a Ruby VM with an integrated NoSQL database, it's a pure object database that uses Ruby for its data manipulation language.
git clone https://github.com/johnnyt/data-migrations-with-maglev.git
cd data-migrations-with-maglev
./script/setup