Spree-Stand-Alone is a project mainly written in RUBY and JAVASCRIPT, it's free.
Spree without spree dependencies
This is a version of Spree [http://spreecommerce.com/], the open source Rails ecommerce system, without any of the spree dependencies (gems, engine etc.).
Extensions and certain generators of the spree system will be inoperable but all the code will be in one place and be completely configurable.
Current version is 0.60.1