http://www.joedog.org/JoeDog/Siege

Benchmarking SquirrelMail
% siege -H "Cookie: squirrelmail_language=; SQMSESSID=10c85281f476600ee102e2db24354612; key=0Ce3/xkJ" \
        -c 10 http://mail.ubuntu/src/right_main.php -b -r 200
** SIEGE 2.66
** Preparing 10 concurrent users for battle.
The server is now under siege..      done.                                                                                                          Transactions:                    2000 hits
Availability:                 100.00 %
Elapsed time:                  64.69 secs
Data transferred:               2.81 MB
Response time:                  0.26 secs
Transaction rate:              30.92 trans/sec
Throughput:                     0.04 MB/sec
Concurrency:                    8.06
Successful transactions:        2000
Failed transactions:               0
Longest transaction:           27.14
Shortest transaction:           0.02