Apple released the latest version of its desktop operating system, OS X 10.8 Mountain Lion, on Wednesday night, a day after posting disappointing quarterly results in the US.
The new operating system brings several features seen in the iOS mobile operating system across to Apple desktops, including Siri-style dictation, messages, notes and reminders.
Mountain Lion costs $A20.99 on Apple's App Store. The company last month said it expected high adoption among an installed user base of 66 million Macs.
A developer version of the operating system was released in February. Apple chief executive officer Tim Cook told investors on Tuesday that Mountain Lion would reach the market on July 25.
Apple reported net income of $8.8 billion for its third quarter of 2012, up $1.5 billion from the previous corresponding quarter.
But the results fell short of analyst estimates, with Apple shares falling five percent in after-hours trading immediately after the announcement.
For the three-month period ending June 30 this year, Apple sold 26 million iPhones, up 28 percent on the previous corresponding period, and 17 million iPads, an 84 percent increase on Q3 2011.
Mac sales were also up two percent to four million for the quarter, while iPod sales dropped ten percent to 6.8 million units shipped.
The company expects revenue of $34 billion for the fourth quarter.
Allie Coyne contributed to this story.
Edited on July 25 at 10.30pm: This story was originally published at 10.30am; it has been updated to reflect the software's availability.