S&box is now an open source game engine
45 comments
·November 26, 20253rodents
adito
Oh, you mean Rust (the game[1]), not Rust (programming language[2]).
raincole
Isn't Rust Unity-based? Was he just too fed up with Unity and decided to roll his own engine?
hnuser123456
S&box was based on UnrealEngine 4 until late 2020. I think Garry wanted to use the latest and greatest engine, then Valve continued to be friendly with him, and even though Valve wanted Source2 to be a VR platform, it was clear desktop was going to remain relevant, but the content creation tools on SteamVR Environments were a cut-down version of what was actually used to make Half-Life Alyx, but they gave Garry all the tools, and he moved to Source2, and built a .net "framework" to make it faster to develop and iterate in Source2. So Garry's tools are now an open version of the closed tools that Valve didn't want to release that they used to make Alyx.
Finally there's another serious competitor to UE and Unity.
enbugger
Yet another one. Along with Stride, Godot, Unigine, O3DE, Flax and tens more. All look like they just want be clone of UE: generic dark UI with inspector, scene hierarchy, asset browser in the bottom and play button in the top. Zero creativity and innovation. Where's Emacs or Vim of game engines which brings its own unique philosophy?
potatoman22
I'd guess S&box is more an extension of Garry's Mod rather than a reaction to Unity
rootlocus
Oooo, I remember Garry Newman! I found his UI library GWEN (GUI Without Extravagant Nonsense) when I was still in uni and working on my game engine. It's been abandoned for 9 years now, nice to see he's still working on cool tech.
Rohansi
He also made the UI framework used by S&box. It's based on HTML/CSS + Razor but is not rendered with a browser.
echelon
That's an amazing story.
I really like all the cultural oddities that Garry's Mod spawned. It was a big piece of machinima / virtual filmmaking history and absolutely paved the way for VTubing and Unreal Engine in film.
Any idea if Facepunch or Valve retain rights to "Skibidi Toilet"?
jquaint
This is cool, though I'm reluctant to give praise when they have been so weird with Linux support on their games.
It was annoying after buying Rust to learn that you can't play on official servers on Linux. The game runs fine on Linux, the devs just don't allow it.
https://www.pcgamer.com/games/survival-crafting/rust-develop...
terabytest
I really struggle to wrap my head around how this engine works. I haven’t used it, but I have experience with Source 1 and its systems and I imagine Source 2 is an extrapolation of that. But I really can’t wrap my head around how they’ve turned it into a scene-based game engine when Source 2 is map-based, how they’ve managed to build a completely different editor that still leverages Hammer maps somehow, and all the other stuff.
1bpp
I've never tried s&box but Source 2 did overhaul the map and asset pipeline quite a bit, everything's a plain mesh instead of BSP and maps are also regular .dmx files, so I'd imagine it's slightly easier to build tools that work on top of it
Rohansi
It is a heavily modified Source 2.
hamdingers
Their site appears down, here's the github repository: https://github.com/Facepunch/sbox-public
tapoxi
It depends on Source 2, which is not open source.
charcircuit
Originally people thought the Source 2 sdk, was going to be released with Half Life Alyx, but it never materialized.
super256
It feels like Valve's management changed a few years (decade?) ago. I remember when they were still shipping SDKs and proper mod support, even for their multiplayer games. Today they are just killing everything that could divert revenue from their cash cow CS2 and shipping a half baked js-based scripting engine for their maps. (And in the meanwhile they kill fan projects like CS:Legacy, which is a whole game and not even a mod, with their army of lawyers. I don't think stuff like this would have happened 13+ years ago).
wavemode
Valve's cash cow is Steam.
All of their games (Dota 2, CS, and the other ones they hardly maintain anymore) are basically just passion projects at this point, lingering on from a bygone age when they were a game development company.
Their most recent title, Half-Life: Alyx, probably only got greenlit because someone internally was able to convince leadership that it would help sell VR headsets.
TehCorwiz
They just opened up the source to TF2 with an SDK not too long ago. Explicitly for modding and community driven development.
jsheard
That's pretty shaky ground too, even if you can overlook the foundation being closed source, Valve aren't really known for supporting their engines very well beyond their own internal needs. They're not trying to be Epic or Unity.
The most obvious aspect to that is that Source 2 doesn't support consoles. Valve don't need it, so they didn't implement it.
embedding-shape
> Valve aren't really known for supporting their engines very well beyond their own internal needs.
Valve has a long history of supporting the modding community and outside users of Source, not sure where you're getting your information from but I don't think they've worked with the Source engine before. One of the biggest and most popular mods of all time was built on Source, and took the world by storm, with pretty big support by Valve through the years as well. Eventually they even bought the whole IP.
jsheard
That was then, in 2025 they don't have a public Source 2 SDK, nor do they generally license the engine to third parties, S&box being the sole exception. They barely have their toes in the middleware game anymore.
Even when they were more open with their tech it was on the basis of "you can play with the tools we used to make Half Life and if your idea is sufficiently Half Life shaped then it will probably work", not trying to be a general purpose toolkit a la Unity.
Rohansi
> Valve aren't really known for supporting their engines very well beyond their own internal needs
They don't need to. S&box uses a fork of Source 2 that is maintained by Facepunch, with Valve's upstream changes merged in as needed.
jsheard
Oh right, that's more reassuring. I guess you'd still have to cut a deal with Valve to use FPs fork commercially though? Which is a wildcard since the licensing terms aren't public as far as I can tell.
null
Topgamer7
I always enjoyed Garry's blog.
It just seemed like a public diary. And a place to vent about dev,life,w/e. He seems to be unapologetic-ally himself.
Although I was pretty sure there used to be more posts (although maybe I'm conflating his posts there with his contributions to his old forums.)
Stevvo
The comments are hilarious. Every file has multiple profanity-filled rants.
benbristow
https://github.com/Facepunch/sbox-public/blob/8b1d58d524c37f...
Log.Error( "Fucked" );
GaryBluto
I'd be interested in calculating the average profanity per-file count for projects that get open-sourced like this.
TehCorwiz
It’s a lot. And more profanity often means better code.
https://arstechnica.com/science/2023/03/is-code-that-contain...
Hamuko
Searching for "fuck" yields 81 files. Searching for "shit" yields 146 files. Only two files for "cunt" though.
justinclift
quantummagic
MIT + copyright retention requirement
Except all third party components that are included in the source, maintain their own license.
nosmokewhereiam
Woohoo, G man made it to HN! I believe in this project and am very hopeful as new game modes and models are added
7bit
As a web dev, I pronounce that sampersandbox.
For those unfamiliar, the studio behind S&box is Facepunch, creators of Garry's Mod and Rust. Facepunch as a company doesn't get much attention but they're wildly successful. Started as just some guy in a bedroom, now ~$100m/year in revenue (all via Steam), $100m in the bank, ~100 employees and almost entirely a company of game developers (maybe 20% of employees are administrative staff). Still owned and ran by the founder, Garry. S&box (and Garry's Mod and Rust) is pure game developers making things they want to make.