Software applications tend to be very large, expensive, and complex to create. There also tend to be changing requirements encountered during their creation (due to changes in marketplace conditions, new offerings from competitors, and additional demands from customers) and new problems that were not foreseen in the design stage. Even after software has been created, the debugging of code tends to take more time than the original coding itself, and need for revisions and improvements may also be expected. Typical software systems are so large and complex that no single individual has a holistic view that takes in every detail. To build such systems, it is essential that there be some way to break down the task into manageable parts that allow there to be a cooperative effort by a team of developers. Practices and tools that work well for a solo programmer often do not...