Copyright, licensing, open source, abandonware
It's important to acknowledge that software informally referred to as "abandonware" has long been considered a legal grey area; it is often difficult or impossible to determine the intention or even existence of a valid rights holder if nobody continues to develop or claim a particular game long after studios go out of business, and often rights acquired in buyouts of long-closed studios are held but not defended or exploited by their rights holder.
All games we work with are freely available in the public domain at present, either with disc images available for public download on preservation sites such as archive.org, or with public downloads or source code offered by the original developers with the intention of making games free.
We have no interest in infringing the copyright or in any way undermining the rights of the creators whom we so greatly admire for bringing these wonderful games into the world, so we tread carefully within reverse engineering practices that are legally considered "fair use", seek out collaboration with original developers and remnant rights holders where any are still contactable, and do not redistribute any original game data where we're not completely sure we have legal license to do so.
In many cases our scratch-built engines do not bundle with original game assets, and can be played either with original store-bought copies of the game, or with freely available disc images, which we provide scripts to help the user download on their own.
For these reasons, we also deliberately omit to specify an existing open source license on our github projects; we do not claim to be in a position to offer a license to all of the work we share on our github, and everything released is "as-is". We only make the assurance that we will not pursue any copyright claim against anyone using the work we release in public on github, but seeking to use our public work for commercial purposes should investigate their legal position with regards to any original or prior rights holders, to what extent reverse engineering fair use applies in their jurisdiction, and what their obligations are in terms of publication of any derivative work. We generally avoid reverse engineering games that are currently available for sale on platforms such as GOG, Steam etc, as presence on such platforms indicates an ongoing intention by a rights holder to exploit that work for profit, which we do not wish to in any way undermine.
If you represent a rights holder of a game that the Lost Engines Project has reverse engineered, please don't hesitate to reach out. We're keen to make sure that we do nothing to cause developers and rights holders to lose revenue from exploiting their intellectual property in any way, and we hope that our work is only beneficial in bringing more publicity and attention to innovative designs that would otherwise have been lost to obscurity.
Similarly if you worked on the development of a game that we have reverse engineered, even if you are no longer the rights holder, please get in touch - we would love to hear from you, and discuss the technical details of your game, and to hear your thoughts on our work.