What is Plan 9?

(fqa.9front.org)

130 points | by AlexeyBrin 6 hours ago

10 comments

  • ori_b 3 hours ago
    Plan 9 is still alive and kicking -- The next Plan 9 conference will be in Victoria, BC in Canada later this year.

    https://iwp9.org/

    9front averages several commits a day:

    https://git.9front.org/plan9front/9front/HEAD/log.html

    • tombert 1 hour ago
      I’ve been on/off playing with 9front on an old laptop. I’ve been having a lot of fun with it, it’s fun to write code for, but i have had a hard time using it as anything but a toy.

      I would love to use it as my main desktop, but ultimately (and kind of unsurprisingly), the blocker is the lack of a modern browser and a lack of video acceleration.

      I’m sure I could hobble something together with virtualization for the former but I don’t see a fix for video acceleration coming.

      Maybe I could install it on a server or something.

    • __turbobrew__ 2 hours ago
  • rcarmo 6 hours ago
    People wanting a Retina-capable drawterm to access Plan9/9front from their Macs are welcome to have a look at https://github.com/rcarmo/drawterm
  • lizknope 2 hours ago
    Why did BSD make Unix sockets something outside of the file system?

    I can do this in bash but I always thought it would be more elegant to do a similar thing in C. I thought Plan 9 handled it more like this?

    cat < /dev/tcp/localhost/22

    SSH-2.0-OpenSSH_10.0

    • somat 43 minutes ago
      They did not have the original unix vision. and it is a lot easier to to design an interface as a programming interface than shoehorn it into a filesystem interface.

      I think having a filesystem interface is pretty great, and plan9 showed it could be done. but having to describe all your io in the [database_key, open(), close(), read(), write(), seek()] interface. can be tricky and limiting for the developer. It is pretty great for the end user however. Having a single api for all io is a super power for adaptive access patterns.

      I think the thing that bothers me the most about the bsd socket interface is how close it is to a fs interface. connect()/bind() instead of open(), recv()/send() instead ot read()/write() but it still uses file discripters so that stuff tends to work the same. We almost had it.

      As much as I like BSD and as great an achievement that the socket interface was, I still think this was their big failure.

      • enriquto 32 minutes ago
        > can be tricky and limiting for the developer. It is pretty great for the end user however.

        This seems to be a great general principle of api design! The best apis are those that are hated by the developer and loved by the end users.

  • pjmlp 5 hours ago
    The transition step between UNIX and Inferno, and between C and Limbo as main userspace language, by its authors.

    Which tends to be forgotten when praising Plan 9.

    • krmboya 5 hours ago
      Is it correct to say Golang is bringing Limbo to the masses?
      • pjmlp 5 hours ago
        Partially, Go still doesn't support a few Limbo features.

        However the influence is quite clear, plus the Oberon-2 style methods and SYSTEM package.

      • rcarmo 4 hours ago
        No, it's bringing Aleph to the masses. Limbo is a cousin, and Dis was certainly very interesting and something I wish had caught on.
        • pjmlp 4 hours ago
          Aleph lacked GC, which Rob Pike considered the main reason for its implementation failure on Plan 9, and initially bounds checking was also missing.

          Two key design difference from Go and its two predecessors.

          Dis is an implementation detail, Go could offer the same dynamism with AOT toolchain, as proven by other languages with ahead of time toolchains available.

          • rcarmo 54 minutes ago
            Dis is not an implementation detail for Inferno, though. And I wish it had gone much further.
      • 9rx 55 minutes ago
        That might be Rust, actually. They have more in common with thoughts about type systems, built-in constructs, deterministic memory usage, etc.

        Limbo looks more like Go on the concurrency front, but that was inherited from Alef/Plan 9. That wasn't what Limbo brought to the table.

  • franciscator 6 hours ago
    I would love to see more Rust on Plan9 implementations, IMHO, could be a good modern combination.
    • solarexplorer 5 hours ago
      I don't know. I use a lot of Swift and C++ and while both are OK languages there is an absurd amount of complexity in these languages that doesn't seem to serve any real purpose. Just a lot of foot traps, really. Coming back to Plan9 from that world is a breeze, the simplicity is like a therapy for me. So enjoyable.

      If "modern" means complex, I don't think it fits Plan9.

      • einpoklum 4 hours ago
        I don't know about Swift, but in C++, the complexity serves at least three purposes:

        1. Backwards compatibility, in particular syntax-wise. New language-level functionality is introduced without changing existing syntax, but by exploiting what had been mal-formed instructions.

        2. Catering to the principle of "you don't pay for what you don't use" - and that means that the built-ins are rather spartan, and for convenience you have to build up complex structures of code yourself.

        3. A multi-paradigmatic approach and multiple, sometimes conflicting, usage scenarios for features (which detractors might call "can't make up your mind" or "design by committee").

        The crazy thing is that over the years, the added complexity makes the code for many tasks simpler than it used to be. It may involve a lot of complexity in libraries and under-the-hood, but paradoxically, and for the lay users, C++ can be said to have gotten simpler. Until you have to go down the rabbit hole of course.

    • AlexeyBrin 5 hours ago
      AFAIK there is no Rust compiler for Plan 9 or 9front. The project is using a dialect of C and its own C compiler(s). I doubt adding Rust to the mix will help. For a research OS, C is a nice clean language and the Plan 9 dialect has a some niceties not found in standard C.

      If you really want Rust, check this https://github.com/r9os/r9 it is Plan 9 reimplemented in Rust (no idea about the project quality):

      R9 is a reimplementation of the plan9 kernel in Rust. It is not only inspired by but in many ways derived from the original Plan 9 source code.

      • euclaise 1 hour ago
        There isn't, though you can run it over wasm on it. I tried it a while back with a port of the w2c2 transpiler (https://github.com/euclaise/w2c9/), but something like wazero is a more obvious choice
    • exitb 5 hours ago
      I’m fairly sure that Rust compiler is bigger than the entire 9front (and 9front has Doom in it).
      • VorpalWay 4 hours ago
        Since Rust depends on LLVM, which is massive, that is almost certainly true. It seems likely even if you don't include LLVM though.
    • anthk 1 hour ago
      You would like Golang more than Rust. At leat the authors (and ex-authors) for sure they are aware of Go, they invented it too.
  • rramadass 4 hours ago
    IMO, the biggest curse of the Internet age is how Distributed OS's did not become mainstream. Maybe we should repackage these as Unikernels and run our apps using their distribution services directly on a hypervisor.
    • zozbot234 2 hours ago
      k8s is really just a distributed OS implemented on top of Linux containers, only with extra facilities for automated tuning, scaling and overall management that are lacking on bare plan9.
      • anthk 2 hours ago
        9front it's far ahead of docker and crappy namespaces running on a libre reimplementation of a dead end Unix version. They did things right from the start. bind it's far superior to anything else.
        • bitwize 1 hour ago
          But... muh scalability!
  • irusensei 6 hours ago
    >9front.org frequently questioned answers

    Knowing that project am I going to be rickrolled?

  • Eikon 6 hours ago
    ZeroFS [0] is very thankful for what it brought to Linux with the v9fs [1] subsystem which is very nice to work with (network native) compared to fuse :)

    [0] https://github.com/Barre/ZeroFS

    [1] https://docs.kernel.org/filesystems/9p.html

    • watersb 6 minutes ago
      I believe that the Windows Subsystem for Linux (WSL, really a Linux subsystem on Windows) uses the Plan 9 network protocol, 9p, to expose the host Windows filesystem to the Linux virtual environment.
  • ruslan 4 hours ago
    Is there Plan9 port for RISC-V (RV32I) ?
    • ori_b 4 hours ago
      There's a 9legacy port, and an in-progress 9front port.

      https://m.youtube.com/watch?v=EOg6UzSss2A

      • ruslan 4 hours ago
        That's interesting, thanks. I feel a need for simple multitasking/networking OS for synthesizable RV32I core (not RTOS like, but more like Unix or CP/M). Would be nice to try Plan9 on it once port is out.
    • chrsw 4 hours ago
      Probably not. And there aren't many 32-bit RISC-V cores with an MMU. I guess you can use a simulator if you found one.
      • ruslan 4 hours ago
        I use one written in SpinalHDL. :-)

        Next question is how much RAM it needs to boot and can it be used without rio ?

  • jes5199 3 hours ago
    I’m not sure it still makes sense to do OS research so close to the metal. Most computing is done up on the application level, and our abstractions there suck, and I haven’t seen any evidence that “everything is a file” helps much in a world of web APIs and SQL databases
    • marssaxman 3 hours ago
      Some of us are still interested in the world underneath all that web stuff!

      Multiple experimental operating systems at multiple abstraction levels sounds like a good idea, though. What sort of system software would you like to build?

    • tombert 1 hour ago
      I didn’t really see the appeal until I learned how to use FUSE.

      There’s something elegant about filesystems. Even more than pipes, filesystems can be used to glue programs together. Want to control your webcam with Vim? Expose a writable file. Want to share a device across the network? Expose it as a file system, mount that filesystem on your computer.

    • Tor3 2 hours ago
      The "everything is a file" approach is nice in many cases, I'm worried though if it works everywhere. Maybe if done right. Subversion (SVN) shows branches as separate file trees.. and ClearCase too (though I'm on thin ice with ClearCase, having used it very little). And I just can't stand the file-oriented way SVN works, I could never get used to it. But there are a lot of other cases where "it's a file" does work, I've experimented with creating Fuse filesystem interfaces to some stuff now and then.
    • GrowingSideways 3 hours ago
      > I haven’t seen any evidence that “everything is a file” helps much in a world of web APIs and SQL databases

      Well for one thing, such an abstraction enables you to avoid web apis and sql databases!

      • moron4hire 2 hours ago
        You're going to have to explain to me how a parametrized request/response system like calling a Web API or making a SQL query can be mapped to reading files. I've seen some stuff that people do with FUSE and it looks like ridiculous circus hoop jumping to making the Brainfuck-is-Turing-complete version of a query system. We have syntax for a reason.
        • zozbot234 2 hours ago
          Plan9 allows for implementing file servers in user space and exporting a whole file tree as a virtual "folder", so it's really more of "everything as a file server". No different than FUSE, really.
          • moron4hire 32 minutes ago
            From what I've seen, Plan 9 fans turn their noses up at FUSE. They say FUSE is not "it", but don't really seem to explain what "it" is to differentiate it from FUSE.

            And as Feynman said, you don't truly understand a thing until you can teach it. So that leaves us in a weird predicament where the biggest proponents of Plan 9 apparently don't understand Plan 9 well enough to teach it to the rest of us.

        • ori_b 2 hours ago
          Typically, if you were writing your hypothetical sql client in rc shell, you'd implement an interface that looks something like:

              <>/mnt/sql/clone{
                  echo 'SELECT * from ...' >[1=0]
                  cat /mnt/sql/^`{read}^/data # or awk, or whatever
              }
          
          This is also roughly how webfs works. Making network connections from the shell follows the same pattern. So, for that matter, does making network connections from C, just the file descriptor management is in C.
          • moron4hire 35 minutes ago
            This is... I don't know. I don't get why I would care to sling SQL over a file system versus a network socket.

            I mean, Postgres could offer an SSH interface as a dumb pipe to psql to just have you push text SQL queries in your application. But it doesn't, it offers a binary protocol over a network socket. All the database engines have had the same decision point and have basically gone down the same path of implementing a wire protocol over a persistent socket connection.

            So yeah, I don't get what doing things this way would give me as either a service provider or a service consumer. It looks like video game achievements for OS development nerds, "unlocked 'everything is a file'." But it doesn't look like it actually enables anything meaningful.

        • GrowingSideways 2 hours ago
          In addition to the sibling comment, you might also consider simply not using the APIs or SQL queries to begin with. Many people have entire careers without touching either.