Maybe was one of the first game engines for the public. DIV Games Studio is a complete solution to develop games for MS-DOS and published in 1997 (DIV1) and 1998 (DIV2).
Is a full windows graphic environment with tools for creation and editing 2D graphics (with a complete drawing suit), particle FX, character animations, font character sets, sounds effects and a complete language programming with a syntax between Pascal and C, including an integrated debugger and a full complete documentation with a lot of tutorials and samples.
This engine allow to develop common 2D games with a full of advanced graphic features, and pseudo 3D games using the Mode7 and later, with DIV2, the Mode8 (3D feature like the original Doom).
DIV Games Studio was very popular at the end of ninetys and early 2000. Was the start point of an entire generation of game developers of nowdays. During the years, the community was develop a multiple forks like Fenix Project (with multiple flavours), CDiv, Div GO, Gemix Studio, Bennu GD, or PixTudio.
Source: https://github.com/VisualStudioEX3/Home/blob/master/pictures/div_games_studio/README.md