Lots of concurrent software is being developed for the now ubiquitous multicore processors. And concurrent programming is difficult because it is quite easy to introduce errors that are really hard to diagnose and fix. One of the main obstacles to concurrent programming is that threads are scheduled nondeterministically and their interactions may become hard to predict and to devise. This chapter addresses the nature of concurrent programming and some classes of concurrency errors. It discusses the application of dynamic program analysis techniques to detect, locate and diagnose some common concurrency errors like data races, atomicity violations and deadlocks. This chapter also mentions some techniques that can help with quality assurance of concurrent programs, regardless of any particular class of concurrency errors, like noise injection and systematic testing, and it is closed by some prospects of concurrent software development.