antecipate: Ready for personal presence solutions?

What Mike calls a "headless presence client aggregator" is nothing more than a publish/subscribe broker where address handles are used as topics... I think that technically, it can be implemented in no time. If this service is aggregating presence information at a client level, the required processing power and memory footprint can be kept very low. A documented API would allow both applications and "watcher" clients to subscribe or publish information to the common presence aggregator, ending up in a fully layered architecture that could benefit any application running on the workstation. The secret here would be to keep it simple.