[HN Gopher] S&box is now an open source game engine
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       S&box is now an open source game engine
        
       Author : MaximilianEmel
       Score  : 156 points
       Date   : 2025-11-26 19:58 UTC (3 hours ago)
        
 (HTM) web link (sbox.game)
 (TXT) w3m dump (sbox.game)
        
       | tapoxi wrote:
       | It depends on Source 2, which is not open source.
        
         | charcircuit wrote:
         | Originally people thought the Source 2 sdk, was going to be
         | released with Half Life Alyx, but it never materialized.
        
           | super256 wrote:
           | 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 wrote:
             | 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.
        
               | npinsker wrote:
               | CS2 makes an enormous and non-negligible amount of money.
        
               | mjr00 wrote:
               | Dota2 as well. Like I'm sure CS2/Dota2 are small
               | _compared to Steam_ , but the revenue from these games
               | alone dwarfs what most other companies are making.
        
               | wavemode wrote:
               | Valve's financials are nonpublic, and any numbers you
               | find are rough, indirect estimates.
               | 
               | In any case, my point was not that these games make no
               | money, but simply that Valve doesn't need them. The total
               | number of people buying games on Steam vastly dwarfs the
               | number of people who play Dota 2 and CS2 (even just
               | counting total players - how much more when you narrow
               | down to players who spend money).
        
             | TehCorwiz wrote:
             | They just opened up the source to TF2 with an SDK not too
             | long ago. Explicitly for modding and community driven
             | development.
             | 
             | https://www.teamfortress.com/post.php?id=238809
        
         | jsheard wrote:
         | 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 wrote:
           | > 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 wrote:
             | 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.
        
               | embedding-shape wrote:
               | S&B existing and being what it is, effectively makes it
               | the Source 2 SDK, although it's not from Valve. But fair
               | point Source 2 isn't licensed to others, I think the
               | expectation is that if you wanna build a Source 2 game,
               | you have to use S&B. At least for now, who knows what
               | their ideas and ambitions really lie.
        
               | fngjdflmdflg wrote:
               | >They barely have their toes in the middleware game
               | anymore.
               | 
               | Well they do have Steam Audio but yeah I agree. I think
               | Epic is much better in this space, even though its only
               | source available in practice they do a lot to support
               | engine modifications and also accept external PRs. I
               | think Valve has a lot to gain from open sourcing Source 2
               | and they should realize how important modding was to
               | their initial success. The issue is now they can just
               | print money with Steam so there is no need to invest in
               | modding support.
        
           | Rohansi wrote:
           | > _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 wrote:
             | 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.
        
               | sieep wrote:
               | I doubt its much of a deal. Garrys Mod and Rust have both
               | been wildly successful (which means Valve has made tons
               | of money off them as well)
               | 
               | My point is, if I were Valve id let Garry run wild with
               | my engine--no deal needed. Hes proven himself more than
               | once. Just a thought!
        
               | Rohansi wrote:
               | There is already a deal between Valve and Facepunch. I
               | don't know all the terms but you will need to publish
               | your game to Steam (not exclusively).
               | 
               | https://sbox.game/dev/doc/systems/game-exporting/ (bottom
               | of page)
        
       | Stevvo wrote:
       | The comments are hilarious. Every file has multiple profanity-
       | filled rants.
        
         | fragmede wrote:
         | omg it's great:
         | https://github.com/search?q=repo%3AFacepunch%2Fsbox-public%2...
        
         | benbristow wrote:
         | https://github.com/Facepunch/sbox-public/blob/8b1d58d524c37f...
         | 
         | Log.Error( "Fucked" );
        
         | GaryBluto wrote:
         | I'd be interested in calculating the average profanity per-file
         | count for projects that get open-sourced like this.
        
           | TehCorwiz wrote:
           | It's a lot. And more profanity often means better code.
           | 
           | https://arstechnica.com/science/2023/03/is-code-that-
           | contain...
        
         | Hamuko wrote:
         | Searching for "fuck" yields 81 files. Searching for "shit"
         | yields 146 files. Only two files for "cunt" though.
        
       | hamdingers wrote:
       | Their site appears down, here's the github repository:
       | https://github.com/Facepunch/sbox-public
        
       | iFire wrote:
       | Can we use the team fortress 2 release of source?
       | 
       | Oh. It's a modding sdk.
       | 
       | https://github.com/ValveSoftware/source-sdk-2013
        
         | rstat1 wrote:
         | and also source 1
        
       | terabytest wrote:
       | 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 wrote:
         | 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 wrote:
         | It is a heavily modified Source 2.
        
       | 3rodents wrote:
       | 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.
        
         | rootlocus wrote:
         | 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.
         | 
         | [1] https://github.com/garrynewman/GWEN
        
           | Rohansi wrote:
           | He also made the UI framework used by S&box. It's based on
           | HTML/CSS + Razor but is not rendered with a browser.
           | 
           | https://sbox.game/dev/doc/systems/ui/razor-panels/
        
         | echelon wrote:
         | 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"?
        
         | raincole wrote:
         | Isn't Rust Unity-based? Was he just too fed up with Unity and
         | decided to roll his own engine?
        
           | potatoman22 wrote:
           | I'd guess S&box is more an extension of Garry's Mod rather
           | than a reaction to Unity
        
           | hnuser123456 wrote:
           | 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 wrote:
             | 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?
        
               | aDyslecticCrow wrote:
               | Who cares about the UI. A game engine is the library code
               | needed to make games, not the editor UI. Just use vim to
               | edit your files if that's what you want.
        
               | wvbdmp wrote:
               | I don't understand this take. The abundance of game
               | engines has never been greater, both open and
               | proprietary. As has the abundance of indie games. Some
               | people make a distinction between more batteries-included
               | engines with editors etc. and "game frameworks", which
               | are supposedly more bare-bones libraries such as Bevy or
               | Babylon.js. Maybe that's what you're after?
        
               | lukan wrote:
               | "Where's Emacs or Vim of game engines which brings its
               | own unique philosophy?"
               | 
               | All forgotten in obscurity.
               | 
               | When making a game, people are usually not so much
               | interested in the philosophy of their tools, but shipping
               | things with it as soon as possible.
               | 
               | That means working as expected.
        
               | lelandbatey wrote:
               | Complaining about the UI color and button layout of an
               | game _engine_ is a bit like comparing aircraft carriers
               | by the color of the rug in the control room. What about
               | the built-in tools for organizing and connecting assets,
               | format support, how user input is handled, the batteries-
               | included ways to model game state, and all the ways of
               | interconnecting all those things _in the code the engine
               | provides_? Does anyone have interesting comparisons
               | /notes around those subjects as it relates to the S&box
               | engine?
        
               | jazzyjackson wrote:
               | I would suppose anyone being creative and innovative with
               | their game engines are happily using their creation
               | without trying to turn it into a community or business
               | model to the point where you would have heard of it.
        
         | adito wrote:
         | Oh, you mean Rust (the game[1]), not Rust (programming
         | language[2]).
         | 
         | [1]: https://store.steampowered.com/app/252490/Rust/
         | 
         | [2]: https://rust-lang.org/
        
       | justinclift wrote:
       | The license: https://github.com/Facepunch/sbox-
       | public/blob/master/LICENSE...
        
         | quantummagic wrote:
         | MIT + copyright retention requirement
         | 
         | Except all third party components that are included in the
         | source, maintain their own license.
        
       | 7bit wrote:
       | As a web dev, I pronounce that sampersandbox.
        
       | Topgamer7 wrote:
       | 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.)
       | 
       | https://garry.net/posts/
        
       | nosmokewhereiam wrote:
       | Woohoo, G man made it to HN! I believe in this project and am
       | very hopeful as new game modes and models are added
        
       | jquaint wrote:
       | 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...
        
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       (page generated 2025-11-26 23:00 UTC)