The MLib (pronounced "M-Lib") is a C software framework that significantly simplifies the development of highly reliable system-level libraries and programs (like daemons/services). It is small, efficient, robust and highly portable, and was designed primarily for embedded systems. (From the FreeType project)
Datadec takes recursive data types modelled on those found in functional languages (Hope, Miranda, Haskell etc) and generates ANSI C code to implement them.