Back with Live Communications Server, Microsoft got more into the online real-time collaboration space and since then they’ve evolved this product into a really capable solution that provides a lot of functionality. Instant messaging, audio/video calling, VOIP phone system integration/replacement, conferencing, desktop sharing, etc.
The only thing I don’t like about it is that they keep changing the name of it 😛
Anything I find useful related to Lync / Skype for Business will go up here for my own reference and if it’s useful, for anyone else also.