Geolith is a highly accurate core for a popular console/arcade system released in the early 1990s, and surviving into the mid 2000s. It is written in modern C and takes a unique approach compared to other emulators for this system. This core focuses on providing a user experience similar to a traditional home console, both by defaulting to home console mode and the use of single-file game files. However, despite this focus, it also maintains full support for playing games in arcade form.
RetroArch is free/open source software, available under the GNU GPL 3.0 license.
It does not contain any copyrighted material by third parties. RetroArch does not condone piracy in any way, shape or form.