In this thesis, we investigate some of the options programmers have when writing a concurrent program. We explore the use of manually created threads, thread-pools, actors, and Software Transactional Memory. We use these techniques to implement case studies of various kinds: a video game, a physical simulation, an image-processing application, and a concurrent data structure. Through-out these case studies, we notice a common thread: concurrency, applied correctly, can improve the performance of a program—but the correct application may not be readily apparent. Concurrency is an important tool in the toolbox of the modern programmer, especially with the rise of multi-core architectures and the increasing prevalence of distributed systems. A...