The easiest way to install ikiwiki is using the Debian package, but you can also download the source and install it by hand. Ikiwiki should work on most unix-like systems.
Ikiwiki is a perl program, and needs a recent version of perl such as 5.8.8. (5.8.0 has been reported not to work).
Ikiwiki requires the Text::MarkDown, URI and HTML::Parser perl modules be installed, and also uses the following perl modules if available: CGI::Session, CGI::FormBuilder (version 3.02.02 or newer), HTML::Template, Mail::Sendmail, Time::Duration TimeDate, HTML::Scrubber, RPC::XML, XML::Simple, XML::Feed, File::MimeInfo.
The tla support also needs the MailTools perl module.
Various plugins use other libraries and utlities; see their individual documentation for details.
If you want to install from the tarball, you should make sure that the required perl modules are installed, then run:
perl Makefile.PL # PREFIX=/dir to install elsewhere
make
make test # optional
make install
See download for where to get it.