Compliance with VoIP standards means that users of his product should be able to connect to any other VoIP infrastructure that supports the standard. This is a terrific competitive advantage over Skype's current closed architecture approach and should really transform the game. With this product, any of the companies that have made VoIP investments will be able to leverage the p2p VoIP phenomenon using LitFiber's product. Ted Shelton: Competition for Skype

The product in question is LitFiber's iTALK2U. Emphasis mine, and a statement I definitely agree with.

Just like I posted, they've rolled in access to a bunch of other networks (AIM, ICQ). Still Windows only. From the screenshots (screen cap below), the UI is terrible. This one is not a winner.

How hard can it be to build an open source FWD/regular SIP plug in for one of the instant messaging clients? It should be possible to share a codebase across platforms so the various IM clients can then build individual plug-ins…