Online Compilers

http://www.codepad.org/

The best online interface for Compiling C, C++, Perl, Ruby, Haskel, Python, Scheme, TCL, Lua, D, PHP and OCaml programs online on the spot.

http://www.comeaucomputing.com/tryitout/

This needs your email to get output. Its a test version.

http://www.delorie.com/djgpp/compile/

This gives final C compiled .EXE file as a downloadable file.

http://www.solve-et-coagula.com/As3Lisp.html

Lisp and Flash Development.

http://tryruby.hobix.com/

This is For Ruby. Excellent for beginners to learn online interactively with their online compiler.

www.codeide.com - once it was working but now it may not be useful

More to Come....