Since the user interface is single-threaded, if a command takes a long amount of time, it will block the user interface from being redrawn or processed. As a result, it is necessary to run long-running operations in a background thread to prevent the UI from hanging.

Although the core Java library contains java.util.Timer, the Eclipse Jobs API provides a mechanism to both run jobs and report progress. It also allows jobs to be grouped together and paused or joined as a whole.