The aim of LucED is to be a fast and responsive X11 text editor with a simple but powerful user interface similar to NEdit. It uses Lua as an embedded scripting language, and features syntax highlighting that is configurable via PCRE regular expressions with arbitrarily nested patterns.
The KoreLogic Expression Language Library (libklel) is a C library that provides a simple expression language that can be embedded in other programs. It does not implement a full programming language, but rather a simpler expression language called KL-EL that is designed to provide arithmetic and logic operations in situations where embedding a full programming language would be overkill. KL-EL can access functions and variables exported from the embedding program, and is statically and strongly typed, which helps ensure that expressions are valid before they are executed. The embedding API is easy to use, and the library itself is very small.