The AT&T Android SDK is a development kit for multiple AT&T APIs i.e. Speech, Advertising, Address Book, and In-App Messaging, written in Java. This SDK provides developers a way to integrate these APIs with their mobile applications using Java.
AOL has just launched a new telephony web service for developers: the Open Voice API. This API is intended to "provide third-party developers and VoIP device manufacturers with open standards protocols that will enable them to easily integrate the AIM Call Out service into softphones, as well as SIP-enabled hardware and cell phones with wi-fi connectivity."