Slashcode itself is based on Apache, mod_perl and MySQL. The MySQL and Apache configs are still being tweaked -- part of the trick is to keep the MaxClients setting in httpd.conf on each web server low enough to not overwhelm the connection limits of database, which in turn depends on the process limits of the kernel, which can all be tweaked until a state of perfect zen balance has been achieved ... this is one of the trickier parts. Run 'ab' (the apache bench tool) with a few different settings, then tweak SQL a bit. Repeat. Tweak httpd a bit. Repeat. Drink coffee. Repeat until dead. And every time you add or change hardware, you start over!