Fibers: Microthreading Library for .NET / Unity
Runtime/Threading/Fibers.cs  
HeaderDoc
(c) 2025 Sator Imaging, Licensed under the MIT License https://github.com/sator-imaging/Unity-Fundamentals
Fibers is a powerful and efficient coroutine/microthreading library for C#
ported from TypeScript ts-fibers.
Basic Usage
// create fibers based on the array
await using var fibers = Fibers.ForEach(
    concurrency: 4,
    tonsOfUrls
    async (url) =>
    {
        return await DownloadAsync(url);
    });
// iterate items in order as they complete
await foreach (var result in fibers)
{
    Console.WriteLine(result);
}