We are looking for a free and user-friendly game engine for writing a MMORPG with a first person (FPS) view (like Mass Effect). Looking at all the engines and libraries available, it is very difficult to make a choice at this early stage, but I do not want to start with one engine only to find out that it will not work half-way through the project. And at this stage we are not interested in writing our own engine from scratch.
So here are the requirements:
1. Free (at least until (if!) we start making money from the game).
2. FPS-like (similar to Mass Effect), but does not need the latest and greatest graphics (we would actually like something lighter that can run on lower-end PC's).
3. The language in which it is written and used is not all that important (Preferences: Object Pascal/Delphi, C#, C++, Python, but C, Java or some scripting language might still be OK).
4. Preferably support for Linux (for the server) and cross-platform (for the clients) (at least Windows & Linux).
5. Fast networking is a must-have.
6. The ability to import Blender models will be nice.
7. Source code availability would also help.
8. An IDE (and possibly WYSIWYG ability) would be nice.
I am new to game programming (although not to programming as such) and the variety of available engines & libraries are almost overwhelming.
A general question: Is it better to use a single game engine for everything or rather use a combination of tools (e.g. Blender for the "human models", something else for the sound, another tool for the maps, another tool for the game-play & game rules, another tool for the networking and authentication parts)?
Some options we are currently considering (I know there' s a lot I have not even looked at yet - so please let me know):
1. glScene (Lazarus/Delphi): does not seem to be a full game engine, but rather only toolkit. Might have some important pieces missing. Not sure how easy/possible it is to import 3D models from Blender or created in other engines (e.g. ioquake3 models).
2. Asphyre Sphinx (Lazarus/Delphi): No Visual Components? (No WYSIWYG). Not full game engine, toolkit only?
3. Cube2 (Sauerbraten). (C++, OpenGL). Looks nice. Can edit maps etc. from game itself! Importing of 3D models? Easily extensible to write MMORPG game rules and logic?
4. ioquake3 (only C?) More abilities then Cube2? No GUI/IDE? Extensible to MMORPG-type game?
5. Allegro (C++/Pascal/...?) Library only? Import of 3D models?
6. MonoGame (C# / XNA). No GUI (in MonoDevelop)? Import of 3D models? Not full game engine, toolkit only?
7. CrystalSpace (C++). Actually used to write MMORPG. Not first person. No GUI for developing maps/3D models? Import of 3D models? Finicky to install on Linux (Debian) with all dependencies.
8. Unity (?C++?). Easy to use & import Blender models. Windows only (but could be used to write windows clients?). Source code? How easy to extend to MMORPG without source code?
9. Panda3D (Python). High level language. No GUI? Import of 3D models/maps? Full game engine or only toolkit/library?
10... any other suggestions?
If you have had experience in using any of these engines or know a better option, please give your opinion on them.