Eclipse is an integrated development environment (IDE). It contains a base workspace and an extensible plug-in system for customizing the environment. Written mostly in Java, Eclipse can be used to develop applications [From Wikipedia].
The Groovy/Grails Tool Suite™ (GGTS) provides the best Eclipse-powered development environment for building Groovy and Grails applications.
Major Flavors of Eclipse
The Spring Tool Suite is an Eclipse-based development environment that is customized for developing Spring applications. It provides a ready-to-use environment to implement, debug, run, and deploy your Spring applications, including integrations for Pivotal tc Server, Pivotal Cloud Foundry, Git, Maven, AspectJ, and more.
TIP
How do I turn off "Automatically Switch to Debug Perspective" mode in Eclipse or its flavours?
1. Go to Preferences -> Run/Debug -> Perspectives ->
2. Select 'NEVER' for the option of 'Open the associated perspective when application suspends'
2. Select 'NEVER' for the option of 'Open the associated perspective when application suspends'