James Strachan created Groovy in 2003 as a programming language for the Java platform.
Groovy is a dynamic language that runs on the Java Virtual Machine and can interact directly with Java classes and libraries. Strachan announced the project in August 2003, and its design drew on ideas associated with languages including Python, Ruby, and Smalltalk.
The language became popular for scripting, build automation, testing, and domain-specific languages. Its concise syntax and optional typing made it convenient for tasks that could be verbose in ordinary Java code. Groovy also became closely associated with tools such as Gradle and Jenkins pipelines.
Grails is not the language itself. Grails is a web framework built with Groovy. Kotlin is another JVM language, but it was developed at JetBrains and appeared publicly later.