Opera Software has released Opera 7.5 Preview 3 for Mac, the first Opera Mac release to use the company's Opera 7.x engine, already available for Windows.

The company's Mac browser has seen a complete rewrite. Opera is offering the preview version for download, and hopes users will offer the company feedback.

Major new features include support for Opera's Presto rendering engine, which the company claims "was rebuilt from scratch for blazing fast speed, improved standards support, and bi-directional text display."

The release also offers a built-in email, news and newsfeed client; support for Internet Relay Chat (IRC); integration with Keychain; Safari bookmark import and other features.

"This release is unfinished and unsupported beta-quality software. It cannot be registered, but will not expire. This release requires Mac OS X 10.1 or later. We recommend always using the latest operating system updates. Please use the latest release of Macromedia Flash," the company warns.

The final shipping version will support Unicode keyboard layouts and synchronize with Address Book.

Further information and a link to download the software are available through the Opera for Mac forum.