Siege is an http regression testing and benchmarking utility

ABOUT SIEGE
Siege is an http regression testing and benchmarking utility. It was designed to let web developers measure the performance of their code under duress, to see how it will stand up to load on the internet. Siege supports basic authentication, cookies, HTTP and HTTPS protocols. It allows the user hit a web server with a configurable number of concurrent simulated users. Those users place the webserver "under siege."

PLATFORM SUPPORT
Siege was written on GNU/Linux and has been successfully ported to AIX, BSD, HP-UX and Solaris. It should compile on most System V UNIX variants and on most newer BSD systems. Because Siege relies on POSIX.1b features not supported by Microsoft, it will not run on Windows. Of course you can use Siege to test a Windows HTTP server.

NEWS & RELEASE INFORMATION
SIEGE-2.67 April 15, 2008 07:15 EDT This is the current stable release. It implements HTTP/1.1 cache validation. Since it's primary job is to simulate load, cache validation is off by default. You may activate it in your new .siegerc file. Developers, beta testers and adventurous souls, click HERE for the latest BETA version. It is basically a code cleanup. This is the final beta release. Look for version 2.66 soon.

"This is an excellent application that does something expensive suites don't. ie. It does what the users expects it to do, and does it simply."
-- Sgt. Scrub