ZIO VS cats-effect

Compare ZIO vs cats-effect and see what are their differences.

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ZIO cats-effect
37 22
3,409 1,560
2.6% 2.4%
9.4 9.9
7 days ago 4 days ago
Scala Scala
Apache License 2.0 Apache License 2.0
The number of mentions indicates the total number of mentions that we've tracked plus the number of user suggested alternatives.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.


Posts with mentions or reviews of ZIO. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2022-06-24.


Posts with mentions or reviews of cats-effect. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2022-06-02.
  • Rust Is Hard, Or: The Misery of Mainstream Programming
    15 projects | news.ycombinator.com | 2 Jun 2022
    Scala. With the functional effect systems, like Cats Effect or ZIO, you get superpowers.

    Not only can write programs that are "async", but you also get easy retries (and other tricks), safe refactorability (because of its Pure FP nature), reliable and painless resource management and some other goodies like STM (Software transactional memory).

    It's really that good.




  • Future of monix
    1 project | reddit.com/r/scala | 10 Apr 2022
    Monix already uses a “fibers” system very similar to that of Cats-Effect; CE 3 improved on it, and also introduced a new thread-pool implementation, but that's not what I'm referring to. The model introduced in CE 3 refers to the interruption model, which is incompatible to Monix or Cats-Effect 2, and it is what prevented us from upgrading, since it's a lot of work.
  • I love Scala but I can't stand:
    4 projects | reddit.com/r/scala | 27 Mar 2022
    So limited, so many landmines, eg https://github.com/typelevel/cats-effect/issues/749
  • Trying to decide on Scala or Kotlin
    7 projects | reddit.com/r/scala | 20 Mar 2022
    Cats Effect is a high-performance, asynchronous, composable framework for building real-world applications in a purely functional style https://typelevel.org/cats-effect/
  • I would like a job writing Haskell
    7 projects | news.ycombinator.com | 8 Feb 2022
    > doing FP in Scala versus alternatives

    I think Scala is the language most actual functional programming on this planet takes place these days. Be it just FP or pure FP.

    I especially like pure FP in Scala. One can do that with Cats Effect (from the TypeLevel family of languages) or ZIO. They're both awesome, so check them out and pick what you'll like best.



    You don't even need to reach out to Scala 3 (still not as mature in its tooling support), you can have a great time with the latest Scala 2 (2.13).

    > versus alternatives

    I think of Scala as a opinionated take on ML and a module system that is tailored to JVM (and is seamlessly interoperable with Java) that just happens to have syntax heavy on braces/parentheses. Otherwise, what's not to like? :)

  • Endless4s: a new Scala library to describe event sourced entities using tagless-final algebras, running with built-in implementations for Akka
    2 projects | reddit.com/r/scala | 6 Dec 2021
    https://endless4s.github.io Endless bridges the gap between Cats Effect and Akka Cluster Sharding. It makes it possible to define abstract repository and entity algebras in tagless-final style to describe distributed event sourced domains seamlessly within functional codebases. I'm exited about it, let me know what you think!
  • Why is tpolecat against ZIO?
    10 projects | reddit.com/r/scala | 6 Nov 2021
    3) I don't think it's even possible to write such huge post within an hour provided that you are reading all twits about CE bugs instantly. Are you sure these things were related and that post came out one hour after? I wonder if whoever found this bug within ZIO crew even had permissions to create a bug report for CE on GitHub :) Also, it _wasn't_ fixed within hours, it was rushly patched. Because of it, another bug appeared https://github.com/typelevel/cats-effect/issues/2269 . Granted, this one was fixed quickly as well.
  • Database migrations in Scala
    4 projects | dev.to | 2 Nov 2021
  • New language features since Java 8 to 17
    4 projects | news.ycombinator.com | 24 Oct 2021
    Not the parent, but presumably it would allow for fancy monad stuff like Scala's Cats Effects[0] and Zio[1] which can make async programming easier to follow without having to introduce async/await

    [0]: https://typelevel.org/cats-effect/

  • Java is the best
    5 projects | reddit.com/r/ProgrammerHumor | 30 Aug 2021
    Nothing like cats or ZIO for Kotlin. I do hope I don't have to explain why Kotlin Arrow is not a good replacement.

What are some alternatives?

When comparing ZIO and cats-effect you can also consider the following projects:

Monix - Asynchronous, Reactive Programming for Scala and Scala.js.

cats - Lightweight, modular, and extensible library for functional programming.

Http4s - A minimal, idiomatic Scala interface for HTTP

fs2-kafka - Functional Kafka Streams for Scala

Vert.x - Vert.x is a tool-kit for building reactive applications on the JVM

FS2 - Compositional, streaming I/O library for Scala

Reactor-Scala-Extensions - A scala extension for Project Reactor's Flux and Mono

fs2-grpc - gRPC implementation for FS2/cats-effect

Scala.Rx - An experimental library for Functional Reactive Programming in Scala

doobie-quill - Integration between Doobie and Quill libraries

RxScala - RxScala – Reactive Extensions for Scala – a library for composing asynchronous and event-based programs using observable sequences

Laminar - Simple, expressive, and safe UI library for Scala.js