codepad is an online collaboration tool for exchanging code which also integrates various compilers/interpreters. After entering code, codepad will run it and print the output.
New pads can be created without registration. For each pad you get a short URL for sharing the code.

Codepad provides syntax highlighting depending on the language. Supported languages are C, C++, D, Haskell, Lua, OCaml, PHP, Perl, Python, Ruby, Scheme, and Tcl. It can be also used to share plain text.