Software

MoinMoin: a cross-platform personal wiki

Although I remain a fan of MediaWiki, for a cross-platform personal wiki I can strongly recommend MoinMoin. Entirely Pythonic, in its Desktop mode MoinMoin simply runs on an in-built server. Moreover, because everything is stored as files (rather than in a SQL database) it is trivial to sync between file-systems.

The bottom line: a highly functional wiki that you can carry on a USB and run on any Python-enabled machine.