IBM has released version 8.5 of its Lotus Notes/Domino collaboration software, bringing updated support for the Apple Mac platform and improvements to the way attachments are handled that should lead to welcome savings on storage requirements.

The new release includes enhancements to both client and server components. On the client side, IBM said that Mac OS X users will now get the same experience as Windows and Linux users, which is one reason why the 8.5 version is being announced to coincide with the Macworld 2009 show in San Francisco.

"As near as we can make it, the Mac version now has parity with other platforms," said Darren Adams, IBM's Messaging and Collaboration business unit leader for the UK & Ireland.

While earlier Notes releases were developed for the PC and then ported to the Mac, the move to the Eclipse platform has allowed IBM to develop components that can run cross-platform, Adams explained. The growing popularity of the Mac also drove development.

"A lot of organisations are now looking at the Mac, and it is growing in usage worldwide," he said.

Among other enhancements, Notes users across all three platforms will now be able to make use of the built-in Lotus Symphony OpenDocument Format editors for office documents, while the Calendar tool now allows users to subscribe to, and overlay information from, other calendars, such as a group calendar, within their own system.

However, the most significant improvements in Notes/Domino 8.5 are on the server side. Chief among these is a feature that decreases the storage space taken up by email attachments by up to 70 per cent, according to IBM.

Domino Attachment Object Storage only stores an attachment once per server, regardless of how many instances exist in user inboxes.

"Prior to 8.5, if you sent an email to 20 people all of them had a local copy of the file, which meant it took up 20 times the storage space," explained Adams.

The new way of handling attachments also has the knock-on benefit of boosting overall server performance, and decreasing the time required to back up user mail accounts.

Another new feature, ID Vault, helps firms to manage user IDs by centralising them onto a server. This makes life easier for users who access email from more than one computer, as well as making it easier for admins to back up ID files.

For developers, XPages brings to Notes/Domino many of the features of modern web applications based on Ajax, according to IBM.

Adams said that XPages will allow developers to build new applications or update existing ones with better views and search capabilities, enabling more dynamic applications.

The new capabilities could give a boost to Notes, which many observers feel has been gradually losing market share to Microsoft's Exchange in the corporate groupware sector.

Lotus Notes/Domino 8.5 will ship ahead of IBM's Lotusphere 2009 conference that starts on 18 January, and will be available under the same licensing model as current versions of the software.