# Open Source Licenses
Provenance is free and open-source, and it is built on the shoulders of countless other open-source projects. This page acknowledges the emulator cores, libraries, and tools that make it possible.
For the complete, always up-to-date license list — including all 114 RetroArch cores — see the [**Open Source Licenses**](https://provenance-emu.com/licenses/) page on the Provenance website. That page is automatically synced from the source code and includes live search and filtering.
## Native Emulator Cores
The following cores are built directly into Provenance (not via RetroArch). Each entry links to the upstream project and its license.
| Name | Systems | License |
| ----------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------ |
| [Atari 800](https://atari800.github.io) | Atari 5200, Atari 8-bit | [GPL-2.0-or-later](https://github.com/atari800/atari800/blob/master/COPYING) |
| [Azahar (Experimental)](https://azahar-emu.org) | Nintendo 3DS | [GPL-2.0-or-later](https://github.com/azahar-emu/azahar/blob/master/LICENSE) |
| [BeetlePSX](https://github.com/libretro/beetle-psx-libretro) | PS1 | [GPL-2.0-only](https://github.com/libretro/beetle-psx-libretro/blob/master/COPYING) |
| [Desmume2015](https://github.com/flyinghead/desmume2015) | Nintendo DS | [GPL-2.0-or-later](https://github.com/TASEmulators/desmume/blob/master/desmume/COPYING) |
| [Dolphin](https://github.com/Provenance-Emu/dolphin-ios-jitless) | GameCube, Wii | [GPL-2.0-or-later](https://github.com/dolphin-emu/dolphin/blob/master/COPYING) |
| [DosBox Pure](https://github.com/schellingb/dosbox-pure) | DOS | [GPL-2.0-or-later](https://github.com/schellingb/dosbox-pure/blob/main/LICENSE) |
| [DuckStation](https://github.com/stenzek/duckstation/) | PS1 | [GPL-3.0-only](https://github.com/stenzek/duckstation/blob/master/LICENSE) |
| [EP128Emu](http://ep128emu.sourceforge.net) | Enterprise 128, ZX Spectrum | [GPL-2.0-or-later](http://ep128emu.sourceforge.net/about.html) |
| [EmuThreeDS](https://github.com/emuPlace/emuThreeDS) | Nintendo 3DS | [GPL-2.0-or-later](https://github.com/emuPlace/emuThreeDS/blob/main/LICENSE) |
| [FBNeo](https://github.com/finalburnneo/FBNeo) | Neo Geo, MSX, CPS, ColecoVision | [LicenseRef-FBNeo](https://github.com/finalburnneo/FBNeo/blob/master/src/license.txt) |
| [FCEUX](http://sourceforge.net/projects/fceultra/) | NES, FDS | [GPL-2.0-or-later](https://github.com/TASEmulators/fceux/blob/master/COPYING) |
| [Final Burn Neo](https://neo-source.com) | Neo Geo, MSX, MSX2, Arcade, NES, ColecoVision | [LicenseRef-FBNeo](https://github.com/finalburnneo/FBNeo/blob/master/src/license.txt) |
| [Flycast](https://github.com/flyinghead/flycast) | Dreamcast | [GPL-2.0-only](https://github.com/flyinghead/flycast/blob/master/LICENSE) |
| [FreeIntv](https://github.com/libretro/FreeIntv) | Intellivision | [GPL-3.0-or-later](https://github.com/libretro/FreeIntv/blob/master/LICENSE) |
| [Fuse](http://fuse-emulator.sourceforge.net) | ZX Spectrum | [GPL-2.0-or-later](http://fuse-emulator.sourceforge.net) |
| [Gambatte](https://github.com/sinamas/gambatte) | Game Boy, GBC | [GPL-2.0-or-later](https://github.com/sinamas/gambatte/blob/master/COPYING) |
| [Gearcoleco](https://github.com/drhelius/Gearcoleco) | ColecoVision | [MIT](https://github.com/drhelius/Gearcoleco/blob/master/LICENSE) |
| [Genesis Plus GX](https://github.com/ekeeke/Genesis-Plus-GX) | Genesis, Game Gear, Master System, SG-1000, Sega CD | [LicenseRef-Genesis-Plus-GX](https://github.com/ekeeke/Genesis-Plus-GX/blob/master/LICENSE.txt) |
| [GME](https://github.com/libretro/libretro-gme) | Music files | [LGPL-2.1-or-later](https://github.com/libretro/libretro-gme/blob/master/LICENSE) |
| [Hatari](http://hatari.tuxfamily.org) | Atari ST | [GPL-2.0-or-later](https://git.tuxfamily.org/hatari/hatari.git/tree/gpl.txt) |
| [Mednafen](https://mednafen.github.io) | Saturn, PS1, Lynx, Neo Geo Pocket, PC Engine, PC-FX, Virtual Boy, WonderSwan, NES, SNES, GB, GBC, GBA | [GPL-2.0-or-later](https://mednafen.github.io/documentation/) |
| [melonDS](https://melonds.kuribo64.net) | Nintendo DS | [GPL-3.0-or-later](https://github.com/melonDS-emu/melonDS/blob/master/LICENSE) |
| [Mini vMac](https://www.gryphel.com/c/minivmac/) | Macintosh | [MIT](https://www.gryphel.com/c/minivmac/license.html) |
| [Mu](https://meepingsnesroms.github.io) | Palm OS | [MIT](https://github.com/meepingsnesroms/Mu/blob/master/LICENSE) |
| [mGBA](https://mgba.io/) | GBA | [MPL-2.0](https://github.com/mgba-emu/mgba/blob/master/LICENSE) |
| [Mupen64Plus](https://github.com/mupen64plus) | N64 | [GPL-2.0-or-later](https://github.com/mupen64plus/mupen64plus-core/blob/master/COPYING) |
| [Mupen64Plus-Next](https://github.com/libretro/mupen64plus-libretro-nx) | N64 | [GPL-2.0-or-later](https://github.com/libretro/mupen64plus-libretro-nx/blob/develop/LICENSE) |
| [Opera](https://github.com/libretro/opera-libretro) | 3DO | [LGPL-2.1-or-later](https://github.com/libretro/opera-libretro/blob/master/LICENSES) |
| [PCSX Rearmed](https://github.com/notaz/pcsx_rearmed) | PS1 | [LGPL-2.1-or-later](https://github.com/notaz/pcsx_rearmed/blob/master/COPYING) |
| [PicoDrive](https://github.com/notaz/picodrive) | 32X | [LicenseRef-PicoDrive](https://github.com/notaz/picodrive/blob/master/COPYING) |
| [Play!](https://github.com/jpd002/Play-) | PS2 | [MIT](https://github.com/jpd002/Play-/blob/master/LICENSE.md) |
| [PokeMini](http://sourceforge.net/projects/pokemini/) | Pokemon Mini | [GPL-2.0-or-later](https://sourceforge.net/projects/pokemini/) |
| [Potator](https://github.com/alekmaul/potator) | Supervision | [GPL-2.0-or-later](https://github.com/alekmaul/potator/blob/master/LICENSE) |
| [PPSSPP](https://github.com/hrydgard/ppsspp) | PSP | [GPL-2.0-or-later](https://github.com/hrydgard/ppsspp/blob/master/LICENSE.TXT) |
| [ProSystem](https://gstanton.github.io/ProSystem1_3/) | Atari 7800 | [GPL-2.0-or-later](https://gstanton.github.io/ProSystem1_3/) |
| [Reicast](https://github.com/reicast/reicast-emulator) | Dreamcast | [BSD-2-Clause](https://github.com/reicast/reicast-emulator/blob/master/LICENSE) |
| [SameDuck](https://github.com/libretro/libretro-SameDuck) | Mega Duck | [MIT](https://github.com/libretro/libretro-SameDuck/blob/master/LICENSE) |
| [Snes9x](http://www.snes9x.com) | SNES | [LicenseRef-Snes9x](https://github.com/snes9xgit/snes9x/blob/master/LICENSE) |
| [SNESticle](https://github.com/iaddis/SNESticle) | SNES | [LicenseRef-SNESticle](https://github.com/iaddis/SNESticle) |
| [Stella](https://stella-emu.github.io) | Atari 2600 | [GPL-2.0-or-later](https://github.com/stella-emu/stella/blob/master/License.txt) |
| [TGBDual](https://github.com/libretro/tgbdual-libretro) | Game Boy, GBC | [GPL-2.0-or-later](https://github.com/libretro/tgbdual-libretro/blob/master/COPYING) |
| [TIC-80](https://tic80.com) | TIC-80 | [MIT](https://github.com/nesbox/TIC-80/blob/dev/LICENSE) |
| [VecX](https://github.com/libretro/libretro-vecx) | Vectrex | [GPL-2.0-or-later](https://github.com/libretro/libretro-vecx/blob/master/LICENSE) |
| [VisualBoyAdvance](https://sourceforge.net/projects/vba/) | GBA | [GPL-2.0-or-later](https://github.com/visualboyadvance-m/visualboyadvance-m/blob/master/COPYING) |
| [Yabause](https://yabause.org) | Saturn | [GPL-2.0-or-later](https://github.com/Yabause/yabause/blob/master/yabause/COPYING) |
| [blueMSX](http://fms.komkon.org/blueMSX/) | MSX, MSX2 | [GPL-2.0-or-later](http://fms.komkon.org/blueMSX/) |
| [fMSX](http://fms.komkon.org/fMSX/) | MSX, MSX2 | [LicenseRef-fMSX](http://fms.komkon.org/fMSX/) |
## RetroArch Cores
Provenance also includes 114 [RetroArch](https://www.retroarch.com/) / [libretro](https://www.libretro.com/) cores. RetroArch is a unified front-end for emulator cores built using the libretro API. These cores cover a wide range of additional systems and are licensed individually by their respective upstream projects — the majority under GPL-2.0-or-later.
For the complete list of all RetroArch cores included in Provenance, with individual license links, see the [**Open Source Licenses**](https://provenance-emu.com/licenses/) page on the website.
## License Types
Provenance and its included cores use a variety of open-source licenses. Here is a plain-language summary:
GPL (GNU General Public License) — v2.0 and v3.0
The most common license in Provenance. GPL requires that any distributed software — including apps incorporating GPL code — make their source code available under the same license. Provenance's source code is publicly available on [GitHub](https://github.com/Provenance-Emu/Provenance).
* **GPL-2.0-only** — Version 2 only; cannot be relicensed under later versions.
* **GPL-2.0-or-later** — Version 2 or any later version at your option.
* **GPL-3.0-only / GPL-3.0-or-later** — Version 3, which adds patent protection clauses.
LGPL (GNU Lesser General Public License)
A more permissive variant of the GPL. LGPL allows the library to be linked into non-GPL software without requiring the whole application to be open-sourced, provided the library itself remains under LGPL. Used by a small number of cores (Opera, PCSX Rearmed, GME).
MIT License
A permissive, short license that allows nearly unrestricted use, copying, modification, and distribution — including in closed-source software — as long as the original copyright notice is preserved. Very business-friendly. Used by Gearcoleco, Mini vMac, Mu, Play!, SameDuck, and TIC-80.
BSD Licenses (2-Clause and 3-Clause)
Similar in spirit to MIT: permissive, allowing redistribution with minimal conditions. The 3-Clause variant adds a non-endorsement clause (you cannot use the project's name to promote your product without permission). Used by Reicast and several RetroArch cores.
MPL-2.0 (Mozilla Public License)
A "weak copyleft" license — modified files must remain under MPL, but they can be combined with code under other licenses. Used by mGBA.
LicenseRef-* (Custom Licenses)
Some projects use custom licenses that are not standard SPDX identifiers. These are denoted with the `LicenseRef-` prefix:
* **LicenseRef-FBNeo** — Final Burn Neo's custom non-commercial license.
* **LicenseRef-Genesis-Plus-GX** — Genesis Plus GX's custom license (non-commercial use).
* **LicenseRef-PicoDrive** — PicoDrive's custom license terms.
* **LicenseRef-Snes9x** — Snes9x's custom non-commercial license.
* **LicenseRef-SNESticle** — SNESticle's custom license.
* **LicenseRef-fMSX** — fMSX's custom non-commercial license.
## Provenance Source Code
Provenance itself is licensed under the **BSD 3-Clause License**. The full source code is available at:
[**github.com/Provenance-Emu/Provenance**](https://github.com/Provenance-Emu/Provenance)
## See Also
* [Supported Systems](https://wiki.provenance-emu.com/platforms-and-performance/supported-systems)
* [System-Specific Guides](https://wiki.provenance-emu.com/platforms-and-performance/system-guides)
* [Contributing](https://wiki.provenance-emu.com/help-and-community/contribute)
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Need help? Ask on [Discord](https://discord.gg/provenance).
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