Susan Bradley, senior project manager on the Communications Server team, here. Below, at the Ask-the-Experts event at PDC 2009, Adarsh (software design engineer on the UCMA team) holds up Programming for Unified Communications with Office Communications Server 2007 R2, which published by Microsoft Press in 2009. PDC attendees received a free copy.
Below, an attendee reviews the UCMA poster given out at PDC 2009, which illustrates all the classes and interfaces to the Unified Communications Managed API (UCMA). UCMA is a powerful server-side API to build custom applications that leverage the Office Communications Server platform.