If you would like to create 3D MMORPGs then you should check out these two engines. I have had experience and each one has its own benifits. Here are my reviews on the engine.
Realm Crafter:
Benifits:
Easy to use editors
Easy to learn scripting language
Great Community (Forums and IRC)
Cons:
Direct X7 only (RC2 will have DX9)
Price:$65 and rising
Multiverse:
Benifits
Nice graphcis (DX9 and OpenGL)
Axiom for renderig
XML Support
Easy to use tools
Cons:
Have to script almost everything
Price:Free
So if you are just starting out I suggest Realm Crafter. If you want a challange or are experienced then check out multiverse.
Once I picked up the game, and got home I couldn't stop playing. It is such a good game. Great graphics, controls, and game play. I also like the new Titan mode. This game is definitly better than the other Battlefield games. Great lands to play on aswell.9/10Why 9/10? It takes a while to load, and it has to optomize shaders when you adjust the graphcis options.