If you are using pushover then just go to https://blurbybot.monkeystew.org. If Telegram, just use the /logout command to clear anything residual and then /register command to start the process.
//

Various bots and pushover is as far as I've gone to date. But I do anticipate eventually getting to that push thing depending on what platform I build towards.
//

sqlite is the default and works for a small lite instance. but the receommendation is postgresql which yeilds better performance. There are other servers being written in different languages such as go, java, and some others as well.

riot is just a client. By default it connects to matrix.org as the server. I'm running my own server instance at monkeystew.net and changed a setting in riot to connect to it instead. But because it's a decentralized network I can chat with anyone on any other matrix server or irc or slack or wherever connections exist.

I'm :monkeystew.net if you want to test it out. You can browse the various channels that are bridged with freenode, gitter and slack, or I've also got pnut bridge with public chat rooms and the global feed, you can browse those on monkeystew.net

Yep it is that indeed. But one I think that has the most potential. It's not centralized like so many others are.

http://matrix.org and probably the best client would be http://riot.im It's a open source and federated chat network. Even connects with other networks like irc, slack, and such.

Spamming my friends to get them to join matrix in an effort to reduce some of the chat apps I use while feeding my chat addiction. ?

Lol yeah I did some Java after college and at the time thought it was pretty cool stuff. Wasn't until I started dealing with it on big iron and running into problems with the garbage collection beyond 1.5 gigs of memory that I realized how bad the JVM really was.

Ah yes Turbo Pascal. One of a few programming languages I never used beyond college.