IP communications services - voice, video and chat and the many variations therein - are all the rage again. Startups are sprouting daily. Though some focus just on mobile, many are building cross-platform applications.

When building such a service, the first and most important capability that you need to build is perhaps not so obvious. It is not wideband voice. It is not chat. It is automated (and silent) client software upgrade. 

The venerable operating system has been around almost as long as the computer has been in existence. Though the "computer" has changed - from mainframes to PCs and now to mobile devices and tablets - the role of its operating system is largely similar. The OS abstracts the underlying hardware and provides applications access to those hardware services. These services typically include file system access, network access, graphics and sound, and of course memory and compute. These are accessed via APIs provided by the OS.