If you are coming from an Ant or Maven background, the first question that comes to mind is: why Gradle? We have already discussed this topic in the initial chapters. Then, another important question comes up. We already have lots of build code written in Ant or Maven; now, if a new script needs to be written into Gradle, wouldn't it be tough to manage two build tools? In this chapter, we will explain different techniques to migrate existing Ant or Maven script to Gradle build script. In the first section of this chapter, we will discuss different strategies that can be applied to migrate from Ant to Gradle and later sections will cover strategies from Maven to Gradle migration.