TCEmacs is a TopCoder Arena plugin which closely integrates the Arena applet with Emacs. When you open a problem in the applet, the plugin contacts Emacs with the help of gnuserv and opens two windows - one with the problem description and another with a generated skeleton of the class and test code. When you press the Compile button in the applet, the plugin fetches the code from Emacs. Code generation and processing take place in Emacs, so Emacs Lisp fans will be able to customize it to suit their needs.
Version 0.2 supports C++ and Java quite well.
Version 0.2 (2006-01-06) (21 kB) (Java support and more compact C++ test code)
Version 0.1 (19 kB)