Groovy desc

Runtime-Environments.md

@@ -70,7 +70,9 @@ Scala source codes are compiled to class files with `scalac` compiler and then e
 
 ## Groovy
 
-TODO
+Groovy source codes are compiled to class files with `groovyc` compiler and then executed with `java` runtime, with addition of `groovy-all.jar` standard dependency. Like Java, Groovy uses our [javarun](https://github.com/ReCodEx/utils/blob/master/runners/java/javarun.java) wrapper executor which finds `main` method and executes it.
+
+Internally Groovy is executed with `java` JDK runtime and standard Groovy library is added to this execution. This library is called `groovy-all.jar` and has to reside in `/opt/groovy/lib/groovy-all.jar` unless the solution will not be executable. If Groovy standard library is not provided the execution will probably fail on loading some of the Groovy specific classes.
 
 ## Kotlin