ZQuest Classic started as a classic 80s-style dungeon-crawler game engine, that over time has grown into a more modern engine. It allows much easier creation of dungeon-crawler style games than other big game engines, due to the number of features that are available without the need for any form of programming knowledge. Since 2012, it has scripting capabilities via the ZScript language, developed specifically for the program. While no scripting is required for many features, use of scripting can allow much more complex and fancy interactions, and allows much more creativity in mechanics and design- at the cost of requiring much more work.
Version 2.55 (starting in 2019) is a major turning point in the program, with its features, both ZScript-related and non-scripted, VASTLY expanded. Many features that previously were seen as popular scripted features were added as in-engine features, now easily usable by any user without any programming required. Scripts also gained many more powerful features, as well as a lot of good quality-of-life programming features.