OpenRW is an open source game engine that attempts to reimplement the engine used in the classic GTA III, first released in 2001. In order to ensure better compatibility with modern systems.
It's just a game engine compatible with the original game, it has no assets of its own. To play GTA III using OpenRW, you must own the game and have data installed on your system. If you need a copy of the game, it's available on Steam.
In the current state, it is not possible to complete the game using OpenRW or make significant progress in the game. There are many bugs that need to be fixed and features that need to be developed before anything can be played with OpenRW.
OpenRW runs on macOS and Linux, as well as some BSDs.
OpenRW development is open, you can follow and contribute via project page on GitHub. Also check out the #openrw tag on the @irc.freenode.net IRC channel.
OpenRW is released under the GNU General Public License version 3.
OpenRW development was started by tsjost and danhedron in 2013, when it started as a simple model viewer that evolved into a map viewer. Over time, OpenRW has gained new features such as physics, vehicles, and pedestrians, as well as scripts that make most of the game playable through the OpenRW engine. Now you can start a new game or load a saved game into OpenRW and interact with the world. The development is currently open and anyone can contribute to the project through the Github repository.
The archive contains only the source code, since the author has currently stopped the available downloads of working versions.