Microsoft is not expected to release the Macintosh version of Internet Explorer (IE) 5.0 until late this year, or even early next year. This is because the software giant is refining its Tasman rendering engine, and working on certain end-user features, an official confirmed today.

Microsoft had originally planned to release IE 5.0 for the Mac well before the end of this year, while the Windows version of the Web browser came out in March.

However, Microsoft has provided an interim release, IE 4.5 for the Mac, that the company didn't provide for its Windows version, said Irving Kwong, a product manager for Microsoft's Macintosh Business Unit in San Jose, California.

The extra Mac release includes drag-&-drop installation and improved printing that allows the user to preview content so that it is formatted to fit on one page, among other enhancements, Kwong said.

IE 5.0 for the Mac will feature Microsoft's rendering engine, codenamed Tasman, which the company has been working on for over a year, according to Kwong. IE 5.0 for the Mac will also enable users to automatically fill out Web forms with personal information at the click of a button, he said. In addition, a new auction manager feature will enable users to track online auctions and receive alerts if they are outbid or if auctions close, Kwong added.

"We're trying to deliver a really high quality product, while delivering innovative features and a strong rendering engine," Kwong said.

Meanwhile, the 5.0 version of Outlook Express for the Mac, which usually ships with IE, will be available on schedule as a standalone product before the end of the year. It will also ship with IE 5.0 for the Mac when it is available, according to Kwong.