Emulators and Roms are Free Programs that Simulate Classic Video Games on your Computer Over the last ten years programmers, hackers, and gamers have been using emulators, such as MAME to allow them to play their favorite old console and arcade games on their home computer.
Emulators and roms (the games they play) are illegal in most cases. However, there has not been a significant crackdown on them by the video game and console companies in about five years. The only way that playing an old game on your computer would truly be legal is if you owned a physical copy of the game. Otherwise, you are breaking the copyright laws that apply to the game.
In 2002, some of the video game manufacturers got together with Sony and Nintendo to pressure the courts system in the United States to make it illegal to create, distribute, or own an emulator. The court system would not allow this since it was not interested in the headache that could be caused for the banning of certain types of programs
The court did allow these companies to go after some of the companies and web sites that allowed roms to be downloaded. At the time, many rom sites had to close down because of legal pressure. The court protected many of those that had downloaded roms since it would be a hard case to prove that they knew that they were doing something wrong.
Once the initial strike against roms passed, many new sites popped up online to distribute roms. Sony and the other companies gave up their fight for the time being. There was not any major action directly against roms until last year when some companies brought up a question about old games that no longer had owners.
These games, called Orphans, are games that were created and copyrighted by companies that no longer exist. The companies that were bringing this up were trying to see if they could buy the rights, and go after rom sites. This case has been tabled into oblivion.
Many companies such as Capcom and Atari started coming out with compilation games that covered many of the old games that people were downloading in rom format. While many of these compilations did well, the roms and emulators still exist.