Nice software tool for link bilding (not for reciprocal link exchange only, as it is written in description), covers almost all aspects of link development, provides a lot of useful information (PR, LPs, AR, etc), cool integrated mail client (those who have tried this will agree that this can save hours), support for SEs APIs, and many other features.

Hmmm... I've tried both Windows and Mac versions - LinkAssistant for Windows is a bit more stable. :\ But this is the only link building software of such high level for Mac - so we'd better start using it right now, and wait for these tiny problems to be fixed.