In the latest of a series of legal battles by Take-Two Interactive, the developers of the re3 project are being sued by the company in the state of California.
What's so significant about this particular project is that it's built on completely reverse engineered source code of Grand Theft Auto 3 and Grand Theft Auto: Vice City. It's also been ported over to the Nintendo Switch, Playstation Vita and Nintendo Wii U.
Under US law, reverse engineering is generally legal. To further minimise encroachment of the law, the developers avoided using any leaked source code, and any copyrighted assets such as music, dialogue and images. Rather, players need to own the original game in order to get those assets.