Frank’s written a tutorial style mdbook on Differential [0] that I highly recommend in addition to his blog posts. There’s also the research paper on the spawned the Timely and Differential projects, Naiad [1].

If you get into it, the library itself is well documented on docs.rs and there’s an active Gitter channel.

(Disclaimer: I work with Frank at his company, Materialize.)

[0]: https://timelydataflow.github.io/differential-dataflow/

[1]: http://sigops.org/s/conferences/sosp/2013/papers/p439-murray...