TechCrunch reports that Google has released a set of components called Libjingle, which will allow third party applications to interoperate with Google Talk's peer-to-peer and voice calling capabilities. The components include source code and are being released under a liberal license, allowing for free incorporation into commercial and non-commercial software. From the announcement:
"In addition to enabling interoperability with Google Talk, there are several general purpose components in the library such as the P2P stack which can be used to build a variety of communication and collaboration applications. We are eager to see the many innovative applications the community will build with this technology."
Back in August, Skype introduced the SkypeNet API that promised to "enable developers to access our IM and Presence system and bring it into new applications without needing to have the full version of Skype running on the machine." You can track progress of SkypeNet on the Skype Developer Zone blog.
But it looks like GoogleTalk may have trumped Skype in terms of API features. As Mike Arrington said, "Skype allows integration with the Skype client. What Google has done goes far beyond this, allowing integration with the Google Talk’s VOIP network."
It'll be interesting to see how Skype (now owned by eBay) responds. Google has a lot of experience with APIs and encouraging mashups, particularly with Google Maps. eBay has historically been a bit behind the 8-ball, for example they only made their developer APIs free of charge last month. Skype will need to respond smartly in order to keep Google, the King King of APIs, at bay.