Licenses and source code

Last updated November 1, 2026

BlastEm

/play runs BlastEm, a Sega Genesis emulator by Michael Pavone and contributors, modified by Shared Valley, Inc. (recording and replay, playable quotes, and the WebAssembly port). BlastEm, including our modifications, is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License, version 3, as published by the Free Software Foundation. It is distributed WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Source code

The build this site runs is version 0.1.1:

• Complete source of this build: web-v0.1.1
• The build itself: blastem.js and blastem.wasm.gz
• Repository with every version and its history: github.com/sharedvalley/blastem

The source includes our changes and the scripts that build the WebAssembly version (build_web, and the workflow that publishes each web-v tag).

You can also ask for a copy of the complete source of any version we have published, for at least three years after we last served it, by writing to contact@sharedvalley.com. We will send it at no more than the cost of providing it.

Components in the build

The source repository holds the license notices of every component it includes.

Games

The game bundled with /play is freely redistributable homebrew. Games you load yourself stay on your device. Recordings and quotes shared from any game follow our copyright process.

Fonts

Inter and Press Start 2P, under the SIL Open Font License 1.1.