Polybrew is a project meant to document first, preserve second, the sum total of output created by the homebrew community.

Homebrew, for the purposes of Polybrew, is defined as “unlicensed original works targetting a system which nominally requires a license agreement with the manufacturer as a prerequisite for publication, but released in a manner not competing with the manufacturer's own output”.

To clarify, here is a non-exhaustive list of concrete examples:

• Non-commercial ROMs created by hobbyists and distributed online free of charge are the most typical variant of homebrew, and are obviously in scope.
• Commercial releases distributed in specialist/hobby spaces, which do not masquerade as official cartridges, are in scope.
• Software created for official hobbyist development kits is in scope provided that such a mode of distribution is distinct from official licensing. For example, Net Yaroze software is in scope, but GP2X software is out of scope.
• Software created for microcomputers is generally not in scope - on such platforms, commercial and hobbyist developers were generally on equal footing, so it's much trickier to reason about scope.
• ROM hacks, as not wholly original works, are not in scope. There are other, better spaces dedicated to indexing them. (However, original fan games are in scope.)
• Tools which are homebrew, but serve the sole purpose of interacting with the world of licensed software - for example, save editors - are in a grey area.

Some platforms, due to cultural similarities, are accounted for as homebrew despite not fulfilling the “unlicensed” requirement. These currently are:

• Aquaplus P/ECE

In the future, Polybrew may expand to cover other forms of what could be referred to as a kind of outsider art relative to commercial software development, focusing around creations for niche, well-defined engines, virtual machines or devices.

While it is Polybrew's goal to document as many homebrew works as possible, it is not Polybrew's goal to make them available for download.

If an official download source exists for a given homebrew program, it should always be linked first.

Absent an official download location, homebrew which is known to have been distributed gratis and is not known to contain infringing material is likely to be available to download via links to platforms like the Internet Archive.

Conversely, commercial homebrew (currently being sold and/or never made available gratis) will not be made available to download via Polybrew, even if unauthorized download sources exist for such files.