Hypnos91 wrote:I can't define myself a programmer, I love programming but I do only small projects for myself in the spare time.
Just because you only launch paper and gunpowder rockets doesn't make you a "not a rocketeer." Same with computer software and programming it. That's why there's a difference between hobbyists and full time engineers. (FYI, some of the most elegant code and best algorithms have been created by hobbyists.)
If you want to get a scope the size of MMO code gets to, look at some of the open-source emulators around, such as for Star Wars Galaxies. Some are always larger than others. Age can really bloat the code, too.
The client code is open source. Details are here. (FYI, the page needs updated. The current client requires Java 1.8.xxx.)