Petra Engine is a 3D game engine for retro PCs running DOS and Win9x. It was originally written as part of the Post Apocalyptic Petra game that was developed for the MS-DOS Game Jam #2 in 2020. It also has been ported to a few other systems like Android, GCW0, Linux, macOS, etc with support for both software and 3D hardware accelerated rendering though the focus is on DOS and Win9x PCs. The engine is written in Free Pascal and has an editor written in Lazarus. The code is under the terms of the zlib license.
From here you can download:
Some dependencies you may need: