Life & fun · alternatives · 2026

uThreads is a C++ library that provides lightweight concurrent user-level threads, also called fibers, using cooperative scheduling. These threads run on top of kernel threads to deliver concurrency and parallelism… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. uThreads – Concurrent User Threads in C and C++ launched in 2016; newer entries below may have overtaken it.

1. 1
   A thread hierarchy management library in C▲53

   Non-preemptive Thread Hierarchy Manager. Contribute to gueststar/nthm development by creating an account on GitHub.

   2020 · github.com · its alternatives →

2. 2
   Async tasks in 350 lines of C▲146

   Tasks are a primitive for asynchronous programming and an alternative to working with threads directly. Instead of creating a thread, performing work, then waiting on it using synchronization primitives, you only define a unit of work and let a scheduler decide when and where to execute it. The threads that the scheduler uses are created once and reused for many tasks throughout the program's lifetime. In most cases, creating and executing a task requires not even a single syscall and is a significantly faster operation than creating a thread, resulting in lower latency. Furthermore, tasks…

   2024 · github.com · its alternatives →

3. 3
   Neco – Coroutine Library for C▲145

   Concurrency library for C (coroutines). Contribute to tidwall/neco development by creating an account on GitHub.

   2024 · github.com · its alternatives →

4. 4
   Threadprocs – executables sharing one address space (0-copy pointers)▲64

   This project launches multiple independent programs into a single shared virtual address space, while still behaving like separate processes (independent binaries, globals, and lifetimes). When threadprocs share their address space, pointers are valid across them with no code changes for well-behaved Linux binaries. Unlike threads, each threadproc is a standalone and semi-isolated process. Unlike dlopen-based plugin systems, threadprocs run traditional executables with a `main()` function. Unlike POSIX processes, pointers remain valid across threadprocs because they share the same address…

   Mar 2026 · github.com · its alternatives →

5. 5
   Libconcurrent – Coroutines in C▲91

   :copyright: Concurrent Programming Library (Coroutine) for C11 - sharow/libconcurrent

   2016 · github.com · its alternatives →

6. 6
   Coros – A Modern C++ Library for Task Parallelism▲129

   Hello Hacker News. I’m Martin, a graduate student from Prague, and I’ve been working on Coros, a C++ library for task-based parallelism. After spending some time with OpenMP and oneTBB, I wanted to try building a library using modern features from the C++ standard library. I’ve used coroutines for task encapsulation and C++23 expected for exception handling, while trying to maintain good performance. Additionally, I’ve implemented monadic-like behavior to allow easy chaining of tasks, similar to the monadic operations in std::expected. You can check out the project here:…

   2024 · github.com · its alternatives →

7. 7
   Hydrogen, a multithread non-blocking Linux server framework in Rust▲154

   Multithreaded, non-blocking Linux server framework in Rust - nathansizemore/hydrogen

   2016 · github.com · its alternatives →

8. 8
   RaftLib – Easy, productive parallel programming in C++▲62

   Simple, easy to use stream computation library for C++.

   2016 · raftlib.io · its alternatives →

9. 9
   Evenk C++ concurrency library▲35

   A C++ library for concurrent programming. Contribute to ademakov/Evenk development by creating an account on GitHub.

   2015 · github.com · its alternatives →

10. 10
    Forkrun – NUMA-aware shell parallelizer (50×–400× faster than parallel)▲151

    forkrun is the culmination of a 10-year-long journey focused on "how to make shell parallelization fast". What started as a standard "fork jobs in a loop" has turned into a lock-free, CAS-retry-loop-free, SIMD-accelerated, self-tuning, NUMA aware shell-based stream parallelization engine that is (mostly) a drop-in replacement for xargs -P and GNU parallel. On my 14-core/28-thread i9-7940x, forkrun achieves: * 200,000+ batch dispatches/sec (vs ~500 for GNU Parallel) * ~95–99% CPU utilization across all 28 logical cores, even when the workload is non-existant (bash no-ops / `:`)…

    Mar 2026 · github.com · its alternatives →

11. 11
    A pure C89 implementation of Go channels, with blocking selects▲271

    A pure C (-std=c89) implementation of Go channels, including blocking and non-blocking selects. - GitHub - rochus-keller/CspChan: A pure C (-std=c89) implementation of Go channels, including blocking and non-blocking selects.

    2023 · github.com · its alternatives →

12. 12AR
    A RISC-V core in Racket▲122

    2021 · guillaume.baierouge.fr · its alternatives →

13. 13LT
    Lightweight Threads, Channels and Actors for the JVM▲116

    2013 · blog.paralleluniverse.co · its alternatives →

14. 14
    The Silicon C++14 Web Framework▲140

    A high performance, middleware oriented C++14 http web framework please use matt-42/lithium instead - matt-42/silicon

    2015 · github.com · its alternatives →

15. 15
    I missed the moving blocks, so I built a real Linux disk defragmenter▲97

    Linux filesystem defragger written in Rust and Qt Quick/Kirigami - gbin/defragger

    Aug 2026 · github.com · its alternatives →

16. 16
    A Fast, Malloc-Free C++14 Json Parser and Encoder▲98

    Meta programming utilities for C++14. Merged in matt-42/lithium - matt-42/iod

    2014 · github.com · its alternatives →

17. 17
    Chan – pure C implementation of Go channels▲150

    Pure C implementation of Go channels. Contribute to tylertreat/chan development by creating an account on GitHub.

    2014 · github.com · its alternatives →

18. 18
    I wrote a minimal memory allocator in C▲137

    A fun toy memory allocator (not thread safe, that's a future TODO). I also wanted to explain how I approached it, so I also wrote a tutorial blog post (~20 minute read) covering the code which you can find the link to in the README.

    Nov 2025 · github.com · its alternatives →

19. 19
    A concurrent thread-safe hash map implemented in C++▲17

    A concurrent thread-safe hash map implemented in C++ - kshk123/hashMap

    2017 · github.com · its alternatives →

20. 20NC
    Nanosecond C message logger▲131

    Hello, Some time ago I did a data logger for fun, just to check if I could beat the performance of an old C++ project of mine (mini-async-log) and to avoid letting my multithreading-C skills rust when on a non-programming gig (using Yocto/OE, very little programming). This project is a BSD licensed, producer-wait-free (when using thread-local storage) generic message logger with high performance, decent test coverage, and type-safe C strings (requires C11 or C++ compiler). It was a shame to let this project to die unknown, as I think that it has potential to be used on some niches as…

    2019 · its alternatives →

21. 21
    Pyper – Concurrent Python Made Simple▲156

    Hello and happy new year! We're excited to introduce the Pyper package for concurrency & parallelism in Python. Pyper is a flexible framework for concurrent / parallel data processing, following the functional paradigm. Source code can be found on [github](https://github.com/pyper-dev/pyper) Key features: Intuitive API: Easy to learn, easy to think about. Implements clean abstractions to seamlessly unify threaded, multiprocessed, and asynchronous work. Functional Paradigm: Python functions are the building blocks of data pipelines. Let's you write clean, reusable…

    2025 · github.com · its alternatives →

22. 22
    Threadsafe, SIMD-Accelerated HyperLogLog Implementation▲5

    C++ Implementations of sketch data structures with SIMD Parallelism, including Python bindings - dnbaker/sketch

    2017 · github.com · its alternatives →

23. 23
    Cr – Runs your tasks at maximum concurrency▲83

    Runs your tasks at maximum concurrency. Contribute to cirocosta/cr development by creating an account on GitHub.

    2017 · github.com · its alternatives →

24. 24
    C++11 inline object definitions▲70

    Meta programming utilities for C++14. Merged in matt-42/lithium - matt-42/iod

    2014 · 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 →