Top 7 Scala Concurrency Projects

Akka

33 12,921 9.4 Scala

Build highly concurrent, distributed, and resilient message-driven applications on the JVM

Project mention: Modern Async Primitives on iOS, Android, and the Web | dev.to | 2023-12-06

Kotlin also has a construct for asynchronous collections/streams. Kotlin's version of AsyncSequence is called a Flow. Just as Swift's AsyncSequence builds upon prior experience with RxSwift and Combine, Kotlin's Flow APIs build upon earlier stream/collection APIs in the JVM ecosystem: Java's RxJava, Java8 Streams, Project Reactor, and Scala's Akka.

ZIO

59 3,987 9.5 Scala

ZIO — A type-safe, composable library for async and concurrent programming in Scala

Project mention: The golden age of Kotlin and its uncertain future | news.ycombinator.com | 2024-01-11

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Scala Async

2 1,137 5.9 Scala

An asynchronous programming facility for Scala
pekko

8 1,048 9.7 Scala

Build highly concurrent, distributed, and resilient message-driven applications using Java/Scala

Project mention: Is akka still worth learning to be employable? | /r/scala | 2023-12-07

Pekko is open source, has the same API. So there's no problem there.

ox

3 290 9.4 Scala

Safe direct-style concurrency and resiliency for Scala on the JVM (by softwaremill)

Project mention: Java21/Virtual threads, simplest the most boring scala http server stack ? | /r/scala | 2023-09-24

I want to just block as if there's no tomorrow, no effects / hardcore FP (maybe only something like https://github.com/softwaremill/ox), what would you use? E.g. for http server / db / json ?https://github.com/com-lihaoyi/cask ?

libretto

2 190 9.4 Scala

Declarative concurrency and stream processing library for Scala

Project mention: Synit – A Reactive Operating System | news.ycombinator.com | 2023-07-15

I'm not sure this is actually easy to solve. The basic idea here seems to be that actors coordinate with the help of shared mutable state (the "dataspace"). At this point you're actually back to square one as synchronizing shared state is the core problem with distributed, concurrent systems…
Given that, and the fact that this whole thingy is untyped makes me skeptical. Not even the std. ingredients like type-state, session types, behavioral types, or the like seem to get used. I also don't see linear types here, which go very well with session types / behavioral types, and can help making typing message passing easier.
Also that this approach would be completely network transparent, as I see it, seems like a design flaw. One needs control over the various effects that can occur! Otherwise the points form "distributed systems future work" can't be solved, imho.
And form the practical point of view: There is no Akka / Pekko based Scala implementation? I'm quite surprised, to be honest.
Akka / Pekko is the actor runtime, and Scala is famous for it's eDSL features; besides of course its type-system, which makes thing like Libretto possible, which seems related here:
https://github.com/TomasMikula/libretto
Syndicate-lang looks OTOH more like the usual callback-hell.
But like I've said, I don't get this whole thingy really. I've just clicked through some parts of the web-sites. Most likely I'm just overlooking the elephant in the room. So would be glad to learn more!
(BTW: Very nice web-site design on all the projects. Especially nice typography. Really enjoyed this part while clicking through this stuff.)

batcher

1 17 4.2 Scala

Batch similar requests together transparently
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NOTE: The open source projects on this list are ordered by number of github stars. The number of mentions indicates repo mentiontions in the last 12 Months or since we started tracking (Dec 2020). The latest post mention was on 2024-01-11.