I just want to mention a highly underrated/undervalued program in this arena: Murmur/Mumble. It's open source, easily self-hostable, and both chat and VOIP are

I just want to mention a highly underrated/undervalued program in this arena: Murmur/Mumble. It's open source, easily self-hostable, and both chat and VOIP are encrypted, vis TLS and OCB-AES respectively. The downside is that it is not end-to-end, and a compromised server would compromise communications, which is why I like to self host on something I've hardened myself as opposed to buying the service from somewhere else. Also, it can also be pushed over TOR if you want... I highly encourage anyone who uses teamspeak, ventrillo, etc, to switch to mumble. I use it to keep up with friends and family from all over the world.