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+============================================================
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+Announcing Goblins (the actor model foundation of Spritely)
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+============================================================
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+
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+:date: 2018-10-31 14:40
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+:author: Christopher Lemmer Webber
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+:tags: goblins, actor model, foss, spritely
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+
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+In my last post I talked about
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+`launching the Spritely project <https://dustycloud.org/blog/spritely/>`_
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+in all its ambitiousness.
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+As I said, I plan on releasing it as a series of "demos".
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+What I mean by "demo" is fairly loose: things you can try and see,
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+artifacts to indicate progress as I go.
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+Convergence slowly towards a goal.
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+
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+Over the last week I released the first version of the foundation
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+of this work, which I'm calling
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+`Goblins <https://gitlab.com/spritely/goblins>`_.
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+v0.1, a pre-pre-alpha release, is now out the door.
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+Goblins is an `actor model implementation <https://en.wikipedia.org/wiki/Actor_model>`_
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+for the `Racket programming language <https://racket-lang.org/>`_.
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+I think if you know some Racket, then
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+`the Goblins documentation <https://docs.racket-lang.org/goblins/>`_
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+should be fairly approachable, and I'd love to hear feedback.
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+Not everything is documented, but it should give you a nice taste
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+of what the core ideas are.
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+(Astute readers may observe that Goblins' name shares striking
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+resemblance to `another project I have worked on <https://mediagoblin.org/>`_;
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+this is no coincidence and is indeed a hint as to what I think the
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+future direction of that area of work is.)
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+
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+Most live distributed systems are in some way a language-level actor
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+model implementation, but *knowing* that you're an actor model
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+implementation may change how you do things.
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+(`ActivityPub <https://www.w3.org/TR/activitypub/>`_ is itself an
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+actor model protocol, though I think not all implementors realize that.)
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+Goblins is the third generation of an actor model I've written, the
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+previous ones being `XUDD <https://xudd.readthedocs.io/en/latest/>`_ and
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+`8sync <https://www.gnu.org/software/8sync/>`_.
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+(Maybe if you count the big rewrite I did of 8sync to run it on top of
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+`fibers <https://github.com/wingo/fibers>`_, it could be the fourth
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+generation.)
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+
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+If you read
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+`the Spritely blogpost <https://dustycloud.org/blog/spritely/>`_
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+you'll know that distributed games are part of the long con here.
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+This isn't the first time I've written a game system on top of one of
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+these actor model implementations; in fact if you scroll down on
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+`8sync <https://www.gnu.org/software/8sync/>`_ website you'll
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+(currently) see a video of me
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+`presenting on Mudsync <https://archive.org/details/feb_2017-live_network_coding_8sync>`_,
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+a multi-user dungeon written in 8sync, where in the talk instead of
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+slides I had rooms, and the audience was moving around in the world
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+and I was changing it in response to their suggestions.
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+
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+But the drive of the actor model connected to social distributed games
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+goes back further for me.
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+I initially got interested in an actor model the first time I tried to
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+work on the whole multiplayer game front about a decade ago.
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+A friend and I spent a couple hours experimenting with threads and locks
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+and after the first demo it was obvious that was never going to work.
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+I remembered I had been told by a former coworker that they had used a
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+system that had an actor model + coroutines as its basis;
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+I didn't know what either of those things were yet, but as I looked into
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+them it became clear to me that this was the right route.
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+But one piece since then until recently remained a mystery to me, which
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+was how to manage the complex web of authorization between the objects.
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+
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+Last year at TPAC, the World Wide Web consortium's conference, I was
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+staying with some people who asked me what I would do if I had
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+unlimited time to work on whatever I wanted.
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+I sheepishly admitted to my dream of a federated social web as a
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+distributed game, and expected to be laughed out of the room.
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+I was surprised to find out that nearly everyone I was working with
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+had some background in this same work and dream.
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+This gave me some hope that I wasn't completely foolish, and the
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+observation that even failure in persuing this ambitious dream would
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+probably result in useful artifacts.
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+
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+And last year at Rebooting Web of Trust, I hit a big breakthrough.
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+I had the chance to meet Mark S. Miller in person, someone who's work
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+I read but barely understood at the time, and this meeting in some
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+ways changed the direction of my career.
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+For one thing, it lead to us collaborating on the foundation for the
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+`ocap-ld specification <https://w3c-ccg.github.io/ocap-ld/>`_,
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+which came out of
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+`a paper we collaborated on from that event <https://github.com/WebOfTrustInfo/rebooting-the-web-of-trust-fall2017/blob/master/final-documents/lds-ocap.md>`_
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+(also available in
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+`nicely formatted PDF form <https://github.com/WebOfTrustInfo/rebooting-the-web-of-trust-fall2017/raw/master/final-documents/lds-ocap.pdf>`_).
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+But what I also discovered was that Mark Miller and company had actually
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+built the distributed *and secure* social network dream in the late 1990s
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+and called it Electric Communities
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+(`rare video of it being demonstrated <https://www.youtube.com/watch?v=KNiePoNiyvE>`_,
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+and a
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+`rare video of some of the out-there ideas <https://www.youtube.com/watch?v=kOFzisF7aNw>`_).
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+What I found out was that they had solved most of the remaining questions
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+about authorization and security through object capabilities, and that
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+was through a pile of object capability patterns built on top of the
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+actor model.
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+While Electric Communities did not survive, its foundation of the
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+`the "E" programming language <http://erights.org/>`_ lived on,
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+pulling in many of its good ideas with it.
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+I proceeded to read as much
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+`documentation about E <http://www.skyhunter.com/marcs/ewalnut.html>`_
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+and surrounding `capability patterns <http://erights.org/elib/capability/index.html>`_
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+as I could, and this has majorly influenced Goblins' design.
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+(Don't underestimate the depth of ideas on
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+`erights.org <http://erights.org/>`_
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+just because it looks like an ancient Geocities page... it did come
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+from that era after all...)
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+
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+Another key insight came from discovering the
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+`Object-Capability Security in Virtual Environments <https://www.uni-weimar.de/fileadmin/user/fak/medien/professuren/Virtual_Reality/documents/publications/capsec_vr2008_preprint.pdf>`_
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+paper.
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+I won't go into details on this except to say that it's a must-read
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+for this problem domain, with the caveat that it pulls in a lot of
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+terminology baggage from the object capability (aka ocap) community.
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+The ocap community is one of those groups that has so many of the right
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+ideas but which unfortunately is also drowning in its own verbiage,
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+despite true efforts to make the ideas more accessible.
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+We (and I guess I'm part of this group now, so "we" is appropriate)
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+need to do better, but
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+`it isn't easy <https://en.wikipedia.org/wiki/Curse_of_knowledge>`_.
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+
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+Goblins is still in its very early days.
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+Its api is unstable and it surely has bugs
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+(`this one in particular <https://gitlab.com/spritely/goblins/issues/8>`_
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+I need to deal with, and which even exposed an
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+`underlying bug in Racket <https://github.com/racket/racket/issues/2341>`_,
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+which `did get fixed quickly <https://github.com/racket/racket/commit/d1fe6a6e3e26df403f650ae821aa0adbd3df491d>`_
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+because the Racket community is amazing).
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+Please don't build anything production-oriented on top of it yet.
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+That said, I'd love users to try things.
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+`Check out the docs <https://docs.racket-lang.org/goblins/>`_, see
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+if they jive with you.
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+And keep watching here; more Spritely demos/artifacts/releases
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+on the horizon.
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Christopher Lemmer Webber