From BleedingEdgeWiki

Preamble

Personal Brain is up to Version 4, it's quite a mature product. As a desktop mindmapping tool, it does not follow the Tony Buzan model strictly, it has it's own unique features. PB 3 was a paid version, PB 4 is offered as a 30 day trial with Pro features at the end of which, it becomes a cut down but still useful free edition. PB 4 is written in Java and installed using InstallJ. If InstallJ detects no JRE on your machine, it downloads JRE from Sun. PB 4/Windows is Vista compatible, there is a Mac edition and a Linux edition.

Mentions: [1]

Problems encountered

Ananda has PB 3 working fine. PB 4 installs on the same machine (dual monitor) but does not appear on execution. PB 4 installs on Vista but no editing is possible.