The research NPC is almost done, only 20 or 30 lines of code left. If I can get over my laziness, I should finish it today.
After this NPC is done, I have a few NPCs left:
1. Teacher NPC
2. Mayor NPC
3. Commerce NPC
Basically, the teacher NPC will be in schools. Every player will have a certain number of "learning" points every day (based on their attributes) and with them they will be able to learn new technologies. The player technology IS dependent on the city tech, for example you can't learn how to make a sword before the city researches the metalurgy and weapons construction.
In Eternal Lands, the player knowledge is aquired by reading books. Once you read a book, you start researching it, and, based on your rationality and other attributes you finish researching it sooner or later. You don't have to do anything, except for having your food level over 0. So if you afk and have some macroing program to eat every once in a while, you can finish researching without any effort.
In Barren Moon, things will be different. You will need to go to a teacher NPC (similar to the research NPC) and 'invest' your learning points in actually learning some technology. I am not 100% sure yet what additional features will be involved to make it more interesting (like, wheter or not to keep the idea of having to read a book first) so the next NPC I will work at will be the Mayor NPC. More info about what it will do later on.