Tomb Raider fans have created from scratch what they call a "reimplementation of classic Tomb Raider engines" which support every level in Lara's first five adventures.
Titled OpenTomb, the new engine also supports encrypted TRNG and TREP custom levels and, having being devised from the ground up, is neither a mod, patcher, or DLL of the existing engines.
OpenTomb uses abandoned Tomb Radier engine clones such as the VT Project and OpenRaider, as well as Quake Tenebrae code.
Explaining why they've created a new Tomb Raider given the existance of others, the group behind OpenTomb explains, "Despite the fact that patchers offer lots of customizations, they still operate within almost 15-year old binary with outdated graphics and sound, lack of modern hardware features support, no optimizarions, no proper physics model, and many more. Also, it is much more difficult to insert new features into pre-compiled binary than write it in high-level programming language. Plus, open-source model of OpenTomb allows anyone to contribute to code, with any degree of involvement."
To download OpenTomb and play the games, head through this link. There's more information, including controls and screenshots, on the Tomb Raider forums.
Rise of the Tomb Raider, the next official game from Crystal Dynamics, launches on November 10th for Xbox 360 and Xbox One.