The Web-GUI testing support requires a selenium-rc version that isn't released
yet. So yo must get it via the OpenQA oficial Subversion repostiory:

svn co https://svn.openqa.org/svn/selenium-rc/trunk

To build it you need to get Maven: 

http://maven.apache.org/download.html

Once you have maven, uncompressed and with the JAVA_HOME variable set properly
get in to the trunk of selenium-rc and then into the selenium-server directory 
and do:

/path/to/maven/bin/mvn install

This process could be long. I hope soon we'll have a selenium-rc Debian
package to avoid this :)

Move the generated file target/selenium-server-VERSION-SNAPSHOT-standalone.jar
to a better place (and name) and finally specify the path of your recently 
obtained .jar into the ANSTE config.

Something like this in /etc/anste/anste.conf:

[selenium]
rc-jar = /home/josh/selenium-rc/selenium-server.jar
browser = *firefox /home/josh/firefox/firefox-bin

You should also specify the path of your browser in this manner.

Good luck!

You can contact me on <jacalvo@warp.es> and I'll try to answer your questions.