libscript is a plugin-based library designed to add language-independent extensibility to applications.
It allows to decouple an application from the virtual machines provided by the various scripting languages. The main library, libscript, is a thin layer that provides a language-independent scripting API, allowing the application to register its functions and invoke code to be performed. Libscript then invokes the appropriate plugin (libscript-python, libscript-ruby, libscript-lua, etc.) to run the code. This way, the application can support all those scripting languages without adding each of them as a dependency.
For more information, please go the the Sourceforge page.