I've been using Zim as a desktop wiki for projects ever since Ethan Schoonover (of Solarized fame) recommended it. Highly suggest checking it out! http://zim-wiki.org
As an aside, I loved Solarized but have to mod it... the single mod is to make 'black' actually black. It is a beautiful colour scheme - I particularly like how comments are faded yet perfectly legible in it.