S&box is now open source
Facepunch Studios has officially made s&box open source, turning its long running Garry’s Mod successor into a fully inspectable and hackable project for developers and curious PC gamers. The studio has released the code on GitHub under the permissive MIT license, which means almost anyone can dig in, learn from it, and even build their own projects on top of it.
S&box is built on Valve’s Source 2 engine and is pitched as a modern game creation platform rather than a simple sequel. It keeps the spirit of Garry’s Mod as a sandbox playground but is designed to go far beyond what was possible in the original.
The big catch is that while Facepunch’s own code is open, Valve’s underlying Source 2 code is not. That stays closed source, so you are getting the tools and systems Facepunch has written on top of the engine, not the engine itself.
What the MIT license means for PC developers and modders
By choosing the MIT license, Facepunch is giving users an extremely flexible legal framework. Under this license you can:
- View and study the s&box code to understand how systems, tools, and gameplay logic are built
- Modify and extend the code to improve s&box itself and submit pull requests to the main repository
- Maintain your own fork for standalone games or experiments without paying royalties
- Reuse parts of the code inside your own engine or project as long as you keep the license notice
In other words, this is not just mod support. It is an invitation to treat s&box as a serious development environment. If you are into PC game development, tool building, or just like to poke around in real world codebases, this is a valuable resource.
Facepunch openly acknowledges that this might look strange if you think purely in terms of short term business logic. Giving away years of work with no royalties is not what most studios do. But the team says it is driven more by enthusiasm for what they are building and the opportunities it can unlock for others.
The idea is to create a space where players, modders, and developers can all benefit. More people using and improving s&box could mean better tools, more content, and more visibility for the platform over time.
A spiritual successor to Garry’s Mod built on Source 2
S&box has been in development for a long time. It was first revealed back in 2017 as a project running on Unreal Engine 4. Even at that stage the systems were built to be engine agnostic, with the idea that they could be moved to different tech if needed. Eventually the project shifted to Valve’s Source 2 engine, where it sits now.
Facepunch calls s&box a spiritual successor to Garry’s Mod and a love letter to Source 2. If you remember what Garry’s Mod did for Half Life 2, that gives you a good starting point. Garry’s Mod repurposed the assets and physics of Half Life 2 into a flexible sandbox for building modes, scenes, and completely new types of gameplay. It became a playground where creativity mattered more than traditional structure.
S&box keeps that core idea of flexibility but upgrades it into a more fully fledged development environment. Facepunch describes it as a modern, intuitive, moddable game development environment. The goal is not just to modernize Garry’s Mod but to eclipse what was possible before.
Examples already shown include a variety of different game types and prototypes made entirely within s&box. The platform is intended to let creators build modes, mini games, or more traditional games while all sharing a common toolset and engine underneath. For PC gamers, that could mean a steady pipeline of experimental content that takes advantage of Source 2 tech.
Facepunch also says it intends to keep working on s&box for the next couple of decades. That long term vision suggests ongoing engine level improvements, new tools, and better workflows for creators who commit to the platform early.
Open finances and a community first approach
Going open source with the code is only one part of Facepunch’s push for transparency. Studio founder Garry Newman has also announced that the finances of s&box will be opened up. The reasoning is simple: when you have a paid platform, there is always suspicion that everything is a cash grab. By exposing how the money flows, the studio hopes to build trust with its community.
Newman points to Valve as a model for this sort of ecosystem mindset. Valve allowed Garry’s Mod to exist and succeed on top of its own work rather than simply recreating it in house and taking all the revenue. That decision gave Facepunch its big break and helped build a thriving modding culture around Source.
Now Facepunch wants to pass that opportunity on. Newman says he is already financially comfortable and sees more value in enabling the next generation of creators than in squeezing every possible dollar out of the engine.
The message to aspiring game developers and technical tinkerers on PC is clear. If you are willing to experiment and learn, s&box is meant to be a place where you can build, share, and maybe even launch something bigger, while standing on the shoulders of both Valve and Facepunch.
S&box has a Steam page and is currently planned for a Q1 2026 release. Developers who want to get in ahead of time can request early access through the official s&box website. If you are interested in PC game creation, modding, or just want to explore a modern codebase on top of Source 2, this is a project worth watching closely.
Original article and image: https://www.pcgamer.com/gaming-industry/garrys-mod-successor-s-and-box-goes-open-source-and-even-opens-up-the-finances-garry-says-valve-gave-me-my-chance-im-already-rich-i-dont-want-to-f-ck-anyone-over/
