The Mac OS X update code-named Jaguar could appear earlier than expected, sources say.

Jaguar was to debut in September, but could now be available in August according to technology Web site Cnet.

In May, Apple hinted that the OS would ship by the end of summer, which was interpreted to mean the end of September or October.

At the time Apple CEO Steve Jobs said: "Jaguar should be the operating system that developers focus on from now on – as Apple has stopped developing on OS 9 internally."