There is probably nothing better for a technical wiki. It's usually bundled as part of the cpanel software on cheap webhosting sites.
For $5/m or less you can have something professional looking, rather than the notion document linked above.
And if your community can't collectively (eventually) cough up $5/m for the hosting costs, then you don't have a community anyway, so it would be pointless having a wiki.
dokuwiki is nice. It's a bit different than mediawiki, so you might want to try both and compare to see which you like better.
One of the biggest differences is that Mediawiki is database-backed while dokuwiki is filesystem-backed. Another is that dokuwiki is closer to markdown syntax while mediawiki has its own more complex syntax.
Overall, dokuwiki is notably simpler and easier, but mediawiki might have some more management stuff that could be helpful if the site has lots of activity and needs more moderation.
For a lot of uses, they're pretty comparable and it would come down to preference.
It's the worst platform for developing a wiki.
Closed software, running on proprietary site, with no edits allowed without signing up to the company.
It's great for company use, but it's entirely the wrong platform for creating a valuable resource of information on the internet.