Well, these are green threads, if you need to do actual concurrency you should probably look elsewhere. And, lighweight looks like it refers to the minimal amo

Well, these are green threads, if you need to do actual concurrency you should probably look elsewhere. And, lighweight looks like it refers to the minimal amount of code in the library. Its a handful of fairly short files, enormous by no standards... Besides, if you're writing C, C11 has the atomics support you desire. Not to mention that most programmers should stick to higher level abstractions than atomics (like mutexes).