Catharsis.NET.Commons is a library of extensions for many common .NET types. It can significantly speed up your daily .NET development tasks, relieving you of writing boilerplate code. It implements the popular fluent-kind interface approach and allows many tasks to be performed in a single line of code with joined method calls.
Dynace is a portable extension to the C language which adds object-oriented facilities, including classes with multiple-inheritance, a meta-object protocol, dynamic dispatching via generic functions, a garbage collector, threads, and an extensive class library, including an optional GUI library. It has complete documentation and a tutorial.
One Step Checkout is a Prestashop module that reduces the checkout experience from six steps to one. It is quick, elegant, and easy to manage, and also allows customers to communicate with store owner through a comment box as well as create an account from the checkout page. The checkout page can be edited and styled.