Have just got Selenium running headless on a RHEL5 VM.

This is kinda-mad, selenium invokes a firefox instance, has it render pages, runs tests against it, then closes the firefox instance down. It does that for very test it runs (clean environment and all I guess). For firefox to run, we need it to think that an X server is running. For that, we use Xvfb.

As this was running on a 64 bit host, I needed to explicitly select the X86_64 version of Firefox, otherwise it would also try to download the i386 version, which would cause all sorts of conflicts.

So, I'm now going to try to repeat the process on real hardware...

As root:

yum install xorg-x11-server-Xvfb
yum install firefox.x86_64
Xvfb -ac :99 &

As a normal user:

wget http://downloads.sourceforge.net/webtestfixtures/webtest-complete-200802...
wget http://release.seleniumhq.org/selenium-remote-control/1.0-beta-2/seleniu...

unzip webtest-complete-20080213.zip
unzip selenium-remote-control-1.0-beta-2-dist.zip
cd webtest-complete-20080213
chmod +x startFitnesse.sh
export JAVA_HOME=/usr/java/jdk1.5.0_16/
export PATH=$JAVA_HOME/bin:$PATH
export DISPLAY=:99
export PATH=/usr/lib64/firefox-3.0.10:$PATH
./startFitnesse.sh &
cd ../selenium-remote-control-1.0-beta-2
java -jar selenium-server-1.0-beta-2/selenium-server.jar -debug -interactive -timeout 600 >> selenium.log 2

Then go to $HOST:8085, and you're away!

Took a day or two to get working on the VM, then about 20 minutes to repeat it.

Hope this helps someone.