SBT, or Scala Build Tool, is a popular build tool for the programming language Scala. It simplifies the process of managing project dependencies, compiling code, and running tests. SBT is designed to work seamlessly with Java projects as well, making it versatile for developers who use both languages. One of the key features of SBT is its incremental compilation, which allows developers to compile only the parts of the code that have changed, speeding up the development process. Additionally, SBT supports a wide range of plugins, enhancing its functionality and enabling integration with various tools and frameworks, such as Akka and Play Framework.