Hello.
Mediawiki is very good, but for programming tasks editing it via web is not very handy since wysiwyg is very limited, pressing 'edit' + 'publish' on any small change and waiting for page loading kins of annoying. I have seen alot of desktop wikis (personal wikis) that are free from such problems. The best example is a 'wikidpad' that has a usage patter of 'focus, edit wiki in-place, minimize'. This is very handy for programming work where you need to make small changes to wiki and documentation during development, and documentation is written much more often than readed :). But all such desktops wikies are personal - they don't have any wiki sharing (or marginally limited support for it).
So, maybe it's a desktop application exists that can connect to mediawiki and allows to view and edit it via a rich wysiwyg editor? Any hints are welcomed.