The IDE uses a small interface to describe the execution of Java-based classes together with arguments.

The Execution API may be used both to invoke the preexisting (internal and external) executors, and to create custom ones. Running processes may be halted, their exit status may be obtained, and their I/O streams will be displayed in the IDE.

The API, in conjunction with the Datasystems API, also supports association of a specific executor to a given class (file), which can be used to provide special execution support for objects such as applets or servlets.