It all depends on age too. If you are 14 or 15, it is a lot of paperwork for the Employer side. Most places don't like going through the hassle of doing it, so they may have an age limit. Just keep your eyes open.
Well personally I like MMORPG's which are fully RPG's. My opinion is that I prefer when everyone plays a part in the RPing rather than some people trolling or just goofing off and not sticking to the point of the game.
Like Teso said,
Go to CMD Prompt, and type
ipconfig
and find somewhere where it says "IPv4", put that link in your browser and it should lead to whatever is on your Port 80.
DaLightz just took an open source and tried to name it his. I would not recommend playing his, but like Kaz says, you can use the open source at https://github.com/mozilla/BrowserQuest