An emulator is a software that enables one computer (called the host) to behave like another computer or hardware (called the guest). An emulator typically enables the host to run software or use peripheral devices designed for the guest computer or hardware. Emulation refers to the ability of a computer program in an electronic device to emulate (or imitate) another computer or hardware.

A ROM, is a computer file which contains a copy of the data from a read-only memory chip, often from a video game cartridge, a computer's firmware, or from an arcade game's main board.

A BIOS (Basic Input/Output System) is firmware used to perform hardware initialization during the booting process (power-on startup), and to provide runtime services for operating systems and programs.

An image is an archive file that contains everything that would be written to an optical disc, sector by sector, including the optical disc file system.

The goal in Hyperbola is distribute fully free emulators to encourage our users to develop, port and distribute free software (eg. images with fully free distros or games, ROMs and firmware) for those guest computers and hardware provided by those emulators. However Hyperbola is blacklisting emulators which concludes that is only useful to develop and run nonfree software.

There are 3 conditions when an emulator is considered nonfree:

• Free column says No
• Free dev tools for firmware column says No or N/A while Requires firmware column says Yes.
• Free dev tools for games/OS column says No or N/A.

The Free column below does not account for firmware and games/OS; it means the core executable.

N/A means no available.

To clarify it, if there is other text there than Yes or No, green means Yes, red means No, while yellow is equivalent to technically yes or there isn't enough information.