BCU SDK is a C based, high level development system for creating programs for EIB/KNX BCU devices. It includes the GNU toolchain for the m68hc05 architecture (m68hc05-gcc, m68hc05-gdb, newlib). Bus access is possible using multiple methods.
Javum, the Java Virtual Unix Machine, is an ambitious project which aims to provide a full virtualized Unix environment including C compiler (GCC), Unix-like API, shell, and command line tools, inside of a JVM. Details @ http://javum.wiki.sourceforge.net