IBM is competing with Sun's real-time Java effort with its development of Metronome, a real-time Java platform that offers a garbage collector that claims to have worst-case delays of only 2 milliseconds. An unnamed client in the defense sector has been testing Metronome and a public report detailing the work will be released in the near future. Garbage collection frees up dynamically allocated memory no longer referenced by an application. However, it should not interfere at the time the system is called upon for immediate response. In June 2005 Sun started licensing the first version of its Sun Java Real-Time System (JRTS) and expects to release a second version by the end of 2005. This version will offer a real-time garbage collector that was developed at Lund University in Sweden. For truly deterministic behavior, the company requires 'no heap' coding that does not allow for garbage collection, and combines 'scoped' memory management techniques, which a skillful programmer can fine tune. The real-time Java suite on a dual-core Sun Workstation running Solaris shows response times of 10 to 20 microseconds. On a dual-core Pentium system, Metronome demonstrates a response time in the 2-ms range, but its techniques do not require a programmer to deal with the fine details of scoped memory management. IBM says its approach simplifies real-time programming in Java since the speed of the real-time garbage collector offers enough speed for most applications. For example, telecom customers require a 10-ms response time, which is well within Metronome's range.