You can get this version from download here: http://opensolution.org/download/
You can test this version here: http://opensolution.org/Quick.Cart/v5.1/
Changes in this version are here: http://opensolution.org/download/Quick.Cart/changeLog.txt
Bug fixes to v5.0: Soon
If You will find bug, something unclear then write it here please!
1. THIS VERSION IS NOT STABLE!!! DON'T USE FOR COMMERCIAL USE, 2. We dont know sure when stable version will be released. It depends from users and tests. Maybe in 1 week. 3. How to upgrade from v5.0 - soon