What are custom engines that you can make on Roblox? For example, Quenty has his open source Nevermore Engine and Rudimentality's gaming engine Tabby Framework has been used in a few open source games. I have also seen developers hint at their game uses a gaming engine they created or that they have updated their game engine. I know this sounds like a nooby question but I was just wondering if someone could explain in depth how you create one and what the purpose of one is?
NOTE: I realize I didn't post any code here but this is more of a generic question about scripting. Also I am not requesting someone create one, I am asking for an explanation.
