IBM has announced the launch of business grade Open Document Format (ODF)-based application services.
The general availability of Lotus Symphony 1.0 for businesses gives them fully supported tools for creating and sharing documents, spreadsheets and presentations.
The move is seen as a full-blooded challenge by IBM to place open-source ODF-based apps directly against Microsoft's proprietary Office suite of apps.
Although Lotus Symphony is a free download from the web with free online, moderated support, IBM is announcing fee-based services to support the needs of large organisations.
This optional service, IBM Elite Support for Lotus Symphony 1.0, delivers unlimited remote technical support at a level consistent with other IBM software products, via an annual subscription to IBM's Passport Advantage or Passport Advantage Express volume licensing programmes.
IBM said Lotus Symphony "could save a company with 20,000 employees £4m in software licence fees, or potentially more than £2m in software renewal fees", but did not specify what it was benchmarking the figure on.
IBM said that if that same firm chose to switch to Symphony for only half of its employees, it could still save several million pounds in licence or renewal fees, even if it subscribed to IBM's Elite Support services at £12.50 per user for 1,000 employees.
Launched in September 2007, Lotus Symphony has been downloaded by nearly a million individuals in an open public beta programme.
IBM said, "A growing number of businesses are considering decisions to renew their Microsoft Office licensing agreements, and move up to Office 2007 and Vista.
"Lotus Symphony 1.0 provides a timely and cost-effective alternative, tested by nearly 1m people worldwide."