Personal wiki

Why not Evernote (etc.)?

 * 1) Not public.
 * 2) Doesn't have links between pages. Links work pretty well on the web. Links match how we put things together in our own head: they allow more complex organisation of information.
 * 3) No (sane) collaborative options. A personal wiki that's on the web can be selectively open to allow collaboration from others on particular pages.

Problems with other personal wikis

 * Solutions like VoodoPad are tied to particular OSes (Mac OS X, iOS). The web browser is universal.
 * Some personal wiki systems don't have version control and/or store data in binary blobs. The latter prevents the use of Git/SVN etc. for effective version control. MediaWiki has it built in.

Friends with personal wikis

 * Tantek Çelik