5. thread library - a basic C thread library, libfiber, was written. It is implemented using two techniques for fibers and Linux kernel threads. This library provides an extremely simple implementation for creating, destroying and scheduling fibers or threads. It should only be used as an example for learning about how threads are implemented, since there are many issues with signals and synchronization. For real applications there are more polished libraries such as pthreads for kernel threads or GNU Portable Threads (Pth) for user space threads.