Open XMPP Alternatives to Google Talk

After Google’s much-publicised decision to replace Google Talk with Hangouts and drop XMPP support in the process, many people have been looking for alternative XMPP servers that allow connecting through standards-based clients and support federation with other servers. I figured this would be a good time to list a few servers I have used and recommend. Naturally, this is only a small subset of all publicly available XMPP servers. Which is best for you pretty much depends on what you want and what you need … [...]