Programming Language

Is the wiki software written in PHP, Perl, ASP, JSP, Ruby, Python, or something else ?

This is one of the key defining features of a wiki engine, which will help you whittle down which software you want to use. For example, there's no point downloading JSPwiki if your webserver isn't capable of running JSPs. If you know what kind of languages your webserver can support, then you can narrow down your choices in this way.

If you haven't chosen a webserver yet, then your choice is still wide open, but most people who are running a wiki, or thinking of doing so, tend to have experience administrating a particular type of webserver, and running/tinkering with web applications written in a particular programming language. You should already have a pretty good idea about this; otherwise, you should learn a bit more about it first, or simply opt for a 'hosted' wiki solution (running on someone else's webserver).

The majority of wiki engines are written in PHP, just because this seems to be the most popular language for open-source web application development, but wikis are also available in Perl, JSP, ASP, Ruby, Python and others.