Dev tools · alternatives · 2026

24 alternatives to Swimmer

An async task pooling and throttling utility for JS

Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Swimmer launched in 2018; newer entries below may have overtaken it.

1. 1
   Code Podcast 3: Concurrency – Event Loop & Coroutines▲54

   Concurrency in UIKits, browsers and web servers

   2016 · soundcloud.com · its alternatives →

2. 2
   FlowTime▲72

   A Pomodoro-driven timer for Chrome

   2015 · chromewebstore.google.com · its alternatives →

3. 3
   NotebookJS▲109

   Scientific computation for JavaScript

   2016 · datazar.com · its alternatives →

4. 4
   KORE.io▲88

   A fast SPDY capable web server for web development in C

   2015 · kore.io · its alternatives →

5. 5SR
   Space Rock, a realtime JavaScript framework▲7

   2015 · space-rock.meteor.com · its alternatives →

6. 6
   Windsock.js – A flux inspired library for building web applications▲6

   2016 · github.com · its alternatives →

7. 7
   Razorframe▲5

   a Node.js library for kickstarting real-time apps at scale

   2016 · github.com · its alternatives →

8. 8KT
   KillerTask: the solution to AsyncTask implementation (in Kotlin)▲5

   2016 · inaka.net · its alternatives →

9. 9NN
   Nhx – Node.js Hybrid eXecutor (a uvx inspired tool)▲6

   Jan 2026 · npmjs.com · its alternatives →

10. 10SA
    Starlette – An asyncio Web framework for Python▲8

    2018 · starlette.io · its alternatives →

11. 11JM
    Jindo – minimalist reactive backend for JavaScript applications▲7

    2016 · jindo.io · its alternatives →

12. 12
    Nullstack – A framework for full stack JavaScript components▲7

    2023 · nullstack.app · its alternatives →

13. 13VC
    virtual-clock.js – adjustable timekeeping for simulations/games/etc▲7

    2017 · npmjs.com · its alternatives →

14. 14AW
    Automatic Workerization of JavaScript Code▲9

    2015 · codepen.io · its alternatives →

15. 15
    Eloquent Javascript▲20

    A modern introduction to Javascript

    2014 · eloquentjavascript.net · its alternatives →

16. 16RA
    Roadroller, a heavyweight packer for large JavaScript demos▲6

    2021 · lifthrasiir.github.io · its alternatives →

17. 17LA
    liblb - A Study and Library of Load Balancing Algorithms▲9

    2017 · liblb.com · its alternatives →

18. 18RA
    Ronin – a toolkit for building CLI apps in Node.js easy and fast▲5

    2014 · vdemedes.github.io · its alternatives →

19. 19ET
    engine262 - the self-hosted JavaScript engine▲5

    2019 · engine262.js.org · its alternatives →

20. 20RA
    RateLimitAPI – API for rate limiting in distributed environments▲5

    2023 · ratelimitapi.com · its alternatives →

21. 21
    Sonar▲14

    A linting tool for the web

    2017 · its alternatives →

22. 22IH
    Introducing Hyperapp 1.0 – 1KB JavaScript library for building web apps▲6

    2018 · medium.com · its alternatives →

23. 23BB
    Bit-bundler – simplify the JavaScript bundling experience▲6

    2017 · bundler.bitjs.io · its alternatives →

24. 24MA
    Molten, a modern API framework for Python▲7

    2018 · moltenframework.com · its alternatives →

Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →