MegaZeux

MegaZeux is a game creation system originally released in 1994, it was inspired by Mega Epic Games ZZT and still being developed today. It has many games and it's easy to develop on, it's kinda like Byond but without built in networking or premium. It also runs on many platforms which is an advantage.

Website: https://www.digitalmzx.com/
Source: https://github.com/AliceLR/megazeux/
License: GPL-2.0
Price: Open source (Free)