When I first got into game development, it was because I wanted to make a 3D MMORPG, in the style of Final Fantasy XI (it was a cutting edge game at the time lol).
I came to realize that this was a monumental undertaking that required far more resources than I had. Even starting with Hero Engine, you would need hundreds, if not thousands of man-years worth of art assets to make it look mildly competitive. Hero Engine also requires extensive programming of the server-side in a proprietary language called HeroScript. I have used Hero Engine (in the form of their indie cloud option, "Hero Cloud"). There is no non-programming server solution for MMORPGs. The best, most complete 3D MMORPG servers are Hero Engine and Electrotank ES5 (http://www.electrotank.com/es5.html), both of which require advanced programming experience and tons of work. I have spent years researching MMORPG development, and there is no easy or cheap route.
However, I am not telling you not to make an MMORPG. Instead, what I came to find was that web games were the way for me to go. Browser-based PBBGs ("Persistent Browser-Based Games") are extremely hot right now and for the foreseeable future, and they can cut down on one of the most costly parts of MMORPG development: art asset creation. They can range from text-based to 2D animated, and everything in-between. They are also, by nature, cross-platform since they are part of the Web. They are also more accessible, and allow for easy integration with Facebook, Google+ and other social networks to help get the word out about your game.
If you do decide to at least investigate this option, you could check out New World Engine for text-based MMOs (http://www.nw-engine.com/) all the way up to Isogenic Engine (http://www.isogenicengine.com/) for 2D animated MMORPGs (it doesn't have to be isometric, despite the name of the engine). I know both of the engine creators very well, and they are very passionate and offer tons of help to new users of their engines. Both would require some programming ability, but games made with it are very doable, and complete-able, something a 3D MMORPG engine cannot say when it comes to indie developers. If neither of these fits what you want, I have created one of the most complete lists of PBBG engines out there (http://indie-resource.com/forums/viewtopic.php?f=112&t=4898) and most of them are free and open source!
Best of luck!
Edited by dacypher22, 14 January 2014 - 03:41 PM.