TCEMacs looks like what I want, but I don't see installation instructions, and I can't launch the jar.
I'm assuming you're talking about version 0.2 of this plugin.
If that is correct, have you actually bothered looking at the contents of the
tc_emacs-0.2.tar.gz file offered for download? Besides the .jar file it contains a README that clearly has installation instructions:
Install gnuserv. You can download it from http://meltin.net/hacks/emacs/ or just use a package if your GNU/Linux distribution provides one. The gnuserv must be working before launching the Arena. The easiest way is to put
in your .emacs file. The gnuserv will then be started together with Emacs.
Make sure that you have Emacs/W3 Browser installed in Emacs. You can check it by typing `M-x w3 '.
Put topcoder.el and TCEmacs.jar in some directory. The topcoder.el file should be loaded before using Emacs in the Arena. You can do that by typing `M-x load-library /path/to/topcoder.el ' or you can just place
or, to load the file only when it is needed:
(autoload 'topcoder-set-problem "/path/to/topcoder.el")
in your .emacs file. I had some problems with autoloading, though. The keymap in the TopCoder mode did not sometimes work and I had to reload topcoder.el manually.
Make a work directory and set the topcoder-directory variable to its name. By default it points to a directory named topcoder in your home directory.
Launch the Arena applet and choose Options/Editor/Add. Type in a name (e.g. Emacs), TCEmacs as the entry point and a path to the TCEmacs.jar file in the ClassPath field.
Now choose a problem to solve. If everything went fine, you should see two new Emacs windows, one with a problem statement and the second one with a source code template.