Smoke testing in WebGUI has the goal of testing WebGUI on as many user situations as possible.  That would basically mean these categories:

Operating Systems

• Ubuntu
• Debian
• RHEL

Environments

• WRE
• non-WRE (native environments)

Users

• root
• WebGUI/Apache user

Versions/Branches

• WebGUI 7.5
• WebGUI 7.4
  

Currently (April 2008), smoke tests run on 7.4 and 7.5 on Debian Etch.  There is another 7.5 smoke run on RHEL as root.