Re: Reviewing the Solid protocol

> On 20. Mar 2023, at 18:52, Tim Bray <> wrote:
> At one point back in mid-2020 I tried to look seriously at Solid and just couldn't figure out "what is this and what does it do?" quickly enough, ran out of patience, and turned my attention elsewhere. Are things better now? I.e. is there a good intro that gets to the heart of the matter quickly?

Solid is LDP + Web Access Control.

Solid has morphed LDP a little; some of that should be rectified.
One important addition that Solid should make explicit is the notion
of the intuitive container I proposed 10 years ago [1], so that it
does not clash with LDP’s more lax containers, which also can be useful.

There is reason to simplify the LDP specs by splitting the
spec into three parts for the various containers [2] as was
suggested by Sandro Hawke in 2014, but was deemed too much work at the time.
A better LDP should integrate some of what was learnt in Solid.

Web Access Control can be separated from LDP as it can be used with
any Web API, including WebDAV, Atom, and other protocols.

The spec lacks examples and an illustration to make it easy to read.
But that should be easy to fix.

There is currently a client/server asymmetry between the server
and the client's ability to read the rules. Those two should be equal
citizens. Privacy issues can be dealt with another way.

The evolution of Solid has, in my view, been seriously hampered because
of this decision and has led to many complexities being
built elsewhere in implementations.  It is easy to change since
it is just an arbitrary restriction.

But the ontology of WAC is very generalisable,
being, I believe, a reified version of RelBac for which a
Description logic is available.

I am working on extensions for a friend of a friend and
other types of more interesting rules than the current ones,
and trying to work out how a more general linked data reasoning would


[2] I argue those containers represent different types of speech acts in a
preliminary report

> On Mon, Mar 20, 2023 at 10:45 AM Melvin Carvalho <> wrote:
> st 15. 3. 2023 v 4:32 odesílatel Danny Ayers <> napsal:
> It is in scope for TAG, the W3C and whatever. But the idea your version is the one. If you want to keep the W3C relatively independent, that doesn't work. If Microsoft and Apple have to drop their version of scripts, so should you.
> It's still about bringing the web to its full potential.  Solid is a pretty good effort in that direction IMHO
> What does it do?
> - Adds a social element (started with FOAF)
> - Adds authentication
> - Adds persistent storage, towards a read write web
> - Adds human and machine readable data
> - Adds realtime updates
> - Friendly to humans and agents
> What are the limitations:
> - Still a bit buggy
> - Some UX issues
> - Largely (but not soley) based on turtle, which is a small part of the web
> - Not 100% backwards compatible e.g. requires conneg and few on the web do that
> - Steep learning curve for new developers
> - Lacks plain old JSON interop (personal observation)
> Not the only way of doing things, but definitely something interesting / creative / innovative.  It also lends itself well to interoperability, together with future and past innovations.
> On Sun, 24 Jul 2022 at 15:18, Tim Berners-Lee <> wrote:
> Solid is a growing protocol/movement, and the tech parts of it — the Solid Project — are basically a W3C Community group.
> Solid adds things which the web needed but hadn’t yet standardized, including global single sign-in, standard access control, and a fast API for data read-write between an app and a store (a Solid Pod).  By making the API to the store universal, it means you don’t have to change the store when you make a new app, which completely changes the architecture and markets and business models which are possible. It also leaves individuals empowered rather than exploited.
> Would it be reasonable for the TAG to review the architecture at a high level, or review the protocol?  It would be useful to get a knowledge of the Solid stack in neighboring parts of the technology.
> (A separate future question are the client-client interop specs which are needed for interop between apps, such as contacts, chat, etc.)
> See is where the specs end up after their github-based proces.
> Best wishes
> Tim BL
> --
> ----

Henry Story
WhatsApp, Signal, Tel: +33 6 38 32 69 84‬
Twitter: @bblfish

Received on Monday, 20 March 2023 19:47:38 UTC