Question
Can I Install Additional Software on an UCS System?
Answer
Univention repositories include all of Debian’s software, including editors such as joe. They’re just not part of the officially supported set of packages. Univention calls this distinction “maintained” vs. “unmaintained”. You can simply activate the “unmaintained” repository via a UCR variable and install joe from it. Easy as pie. See section 5.5 of the admin manual 162 for instructions.
Note: Using software from unmaintained repositories will not be covered by Univention Support.
You should definitely avoid adding Debian repositories (or repositories made for Debian/Ubuntu instead of Univention). Univention’s versions are far enough away from standard Debian that you’ll run into problems eventually, e.g. during upgrade time. Don’t do it.