Life & fun · alternatives · 2026

Constexpr.js is a JavaScript library launched in 2021 that enables compile-time computation within JavaScript. It allows developers to evaluate expressions at build time rather than runtime, potentially improving… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Constexpr.js launched in 2021; newer entries below may have overtaken it.

1. 1
   C++ runtime/compile-time detection in constexpr functions▲83

   An approach for runtime detection inside a constexpr function - SaadAhmad/in_constexpr

   2017 · github.com · its alternatives →

2. 2JP
   JavaScript Program Synthesis▲139

   2021 · grgv.xyz · its alternatives →

3. 3
   Faster.js – a micro-optimizing JavaScript compiler▲89

   faster.js is a Babel plugin that compiles idiomatic Javascript to faster, micro-optimized Javascript. - vzhou842/faster.js

   2018 · github.com · its alternatives →

4. 4
   Cronexpr, a Rust library to parse and iter crontab expression▲160

   `cronexpr` is a library to parse and drive the crontab expression.

   2024 · docs.rs · its alternatives →

5. 5WP
   Weekend project, Intro.js▲716

   2013 · usablica.github.com · its alternatives →

6. 6
   Fast.js – faster reimplementations of native JavaScript functions▲323

   Faster user-land reimplementations for several common builtin native JavaScript functions. - codemix/fast.js

   2014 · github.com · its alternatives →

7. 7
   ScrapScript – A tiny functional language for sharable software▲503

   Hi friends, I started casually working on scrapscript in 2015. I built a few compilers over the years to test out various ideas/implementations, and I think I'm finally happy with the overall design. The code is not public yet. Email me at [email protected] if you're interested in joining the core team later this year. Let me know if you have any questions or feedback :)

   2023 · scrapscript.org · its alternatives →

8. 8
   Joy – a Go to JavaScript compiler▲201

   Matt Mueller's personal website for sharing what I've learned about programming, design, entrepreneurship and life.

   2017 · mat.tm · its alternatives →

9. 9AI
   An Isomorphic JavaScript Framework Faster Than React▲337

   2015 · jsblocks.com · its alternatives →

10. 10GN
    GraphicsJS, New Powerful Free Open-Source JavaScript Graphics Library▲124

    2016 · graphicsjs.org · its alternatives →

11. 11
    Automated algorithm translation for Python, C++, C#, JS▲142

    transpile algorithms/libs to idiomatic JS, Go, C#, Ruby - GitHub - pseudo-lang/pseudo: transpile algorithms/libs to idiomatic JS, Go, C#, Ruby

    2016 · github.com · its alternatives →

12. 12MT
    My Turbo Pascal compiler in JavaScript▲101

    2013 · teamten.com · its alternatives →

13. 13GJ
    G9.js – Automatically Interactive Differentiable Graphics▲237

    2016 · omrelli.ug · its alternatives →

14. 14AJ
    A JavaScript UI library for imperative JSX▲41

    I've been building a web UI library for a side project of mine. I thought it might be useful to others, so I'm releasing it as open source. To put it simply, I realized that most of my pain points with React come from its declarative model ui=f(state). So I'm trying something that I'm calling "imperative JSX." Instead of treating JSX as the source of truth for your UI, it essentially becomes a query interface for DOM manipulation. I first had the idea for it a few months ago, and only began writing it in earnest last week, so it's extremely early and nowhere near production-ready. Still, I'd…

    2024 · npmjs.com · its alternatives →

15. 15
    Frpjs – Functional reactive programming library for JavaScript▲36

    Functional Reactive Programming Library for JavaScript - santoshrajan/frpjs

    2016 · github.com · its alternatives →

16. 16AC
    A complete Bash parser in JavaScript transpiled from Go▲89

    2018 · npmjs.com · its alternatives →

17. 17
    JavaScript port of Scientist library for refactoring critical paths▲34

    :microscope: A JavaScript interpretation of the Ruby library Scientist, a library for carefully refactoring critical paths. - bugthesystem/scientist.js

    2016 · github.com · its alternatives →

18. 18CP
    Clojure parser and core library in JavaScript, live on CodeCombat▲57

    2014 · vickychijwani.github.io · its alternatives →

19. 19ID
    I designed a language for code golf, compiling to Common Lisp▲102

    2013 · rhoscript.com · its alternatives →

20. 20
    js.spec, a JavaScript implementation of clojure.spec▲96

    clojure.spec for Javascript. Contribute to prayerslayer/js.spec development by creating an account on GitHub.

    2016 · github.com · its alternatives →

21. 21CB
    Compiled, buildtime atomic CSS in JavaScript and all your favorite APIs▲47

    2021 · compiledcssinjs.com · its alternatives →

22. 22AJ
    A Javascript library to overcomplicate Five▲69

    2014 · jackdcrawford.github.io · its alternatives →

23. 23
    Cancelable async primitives for JavaScript▲84

    Composable async primitives with cancelation, control over scheduling, and coroutines. Superior replacement for JS Promises. - mitranim/posterus

    2017 · github.com · its alternatives →

24. 24
    Matches.js -- Powerful Pattern Matching for Javascript▲96

    Powerful pattern matching for Javascript. Contribute to natefaubion/matches.js development by creating an account on GitHub.

    2012 · github.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 →