Originally Posted by
taralej
For Lordaeron they took a brand new version of the TrinityCore, which already is mostly bug-free. All those 10 years that they worked on the old Molten realms are already done on that new core, albeit from an outer source. Molten did this with the older realms because they wanted to make sure that every fix they did was their own as a quality assurance. It worked out well at first, but now they just can't handle it anymore (IMHO) so they're taking this new core, patching up the minor bugs they find on it, and then porting it to the other realms.