Well first lets define Unified Communications: a set of products that provides a consistent unified user interface and user experience across multiple devices and media types. There have been attempts at creating a single product solution however the most popular solution is dependent on multiple products. Meaning something like using fiber optics for your internet connection will give you the fastest speeds to be able to run a VOIP service and an awesome entertainment services. As a software you have google+ which just took the whole experience and interface to whole different level and theres always MS office.