There are, of course, many more programming languages supported in Linux. Whether you are looking for programming in Forth, Lisp, or FORTRAN, a short search on the Net with your favorite search engine should yield rapid results. A good starting point is the "Other Languages" section in Chapter 13 of Running Linux (O'Reilly).
The cross-compiling and cross-development capabilities of the various language tools will need to be evaluated on a tool-to-tool basis, since few compilers and interpreters lend themselves well to cross-platform development.