Bit's World

Interbench: http://users.on.net/~ckolivas/interbench/
Interactivity benchmark. Measures the system latency under various simulated load conditions. Supports real-time tasks.

Netperf: http://www.netperf.org/netperf/NetperfPage.html
Measures networking performance.

Hackbench: http://developer.osdl.org/craiger/hackbench/
Tests the performance, overhead and scalability of the Linux scheduler.

dbench: http://samba.org/ftp/tridge/dbench/README
Produces filesystem load.

stress: http://weather.ou.edu/~apw/projects/stress/
System load generator (CPU, memory, I/O, disk)