With Skype down what is your alternative?

I would say Hangout is about the best and easiest for us and with external global people we work with and seems closest to Skype in terms of features. We like the desktop sharing and integrates fairly well with both iOS and Androids, can SMS and the most powerful feature to me is to call a user on their phone and add in.

I use https://appear.in - based on WebRTC.

For text or voice? For voice Mumble is far much better and stable

for video I've been using private http://www.blab.im

for text mainly just Facebook messenger (sorry)

for text messages: Telegram Messenger

for audio messages: Telegram Messenger

for (near) real-time audio/video: Hangouts

Have you tried Viber?

Have you tried Tox ?

We've been using qTox for quite sometime. Pretty stable for an alpha release. The only feature lacking is the non-persistent groups and group chats.