There are many ways in which a Scala application can be built. These include the REPL loop and automated compilation within an IDE such as the Eclipse based Scala IDE. However, neither of these is suitable for centrally building large applications as might be found within many commercial organisations. The most popular build environments for Scala are Maven and the SBT. In this chapter we will briefly examine both so that you have a flavour of both tools and the potential benefits and drawbacks of each.