The Java/JVM platform. Sun wrote a large number of specifications to govern how vendors would provide platform features, above and beyond the language specifications and virtual machine specifications.
Wikipedia list of JVM languages:
Rich ecosystem for dealing with data, particularly the relational kind (JDBC).
Numerous implementations; see JVM, the virtual machine
Robocode (Source): Robocode is a programming game, where the goal is to develop a robot battle tank to battle against other tanks in Java. The robot battles are running in real-time and on-screen.
Last modified 06 October 2021