The arrival of AOL for Mac OS X, which had been available only in a beta, or test, version follows the delivery last month of Microsoft Office v. X for Mac OS X, perhaps the most eagerly awaited Mac OS X program.
Although older Macintosh programs work in the so-called classic environment of Mac OS X, programs must be tweaked to take advantage of the operating system's new features such as improved stability and its Aqua user interface.
Analysts have said it is critical for major applications to be available for Mac OS X before use of the operating system will take off. One of the key remaining programs is Adobe Systems' Photoshop, which is not expected to be optimized for OS X until next year.
AOL, a division of AOL Time Warner, is the world's largest online service, with 32 million subscribers.
In addition to adding Mac OS X support, the new version of AOL's software allows members to sort e-mail messages by sender, subject, date or type. It also includes the latest versions of Microsoft's Internet Explorer and Macromedia's Flash software.
AOL and Apple have been working together on several projects in recent months. In November, Apple introduced a new version of its AirPort wireless networking software that allows Mac owners to share an AOL connection within a wireless home network.
"We'll continue to look for opportunities to extend the AOL experience to the Mac community by programming the AOL service in ways that enhance the Macintosh user's experience," Peter Ashkin, president of product strategy for AOL, said in a statement.
Apple released Mac OS X in March and has started including it on new Macintoshes. However, for now, Mac OS 9 is still the default operating system on new machines.