You can download addons to the completion system. This is handy for commands which aren't covered by the default zsh install. Note that any contibutions sent to the zsh-workers list are welcomed: it is better when functions can be included in the default zsh install.
- KDE – Completion for some KDE applications.
- KDESDK – More KDE completion.
- WMI – Window Manager Improved completion.
- Python – Generic completion for Python programs using optparse.
- Ruby – Generic completion for Ruby programs using optparse.