The mighty Microsoft Office is to face a new challenger on the desktop following IBM's launch of a free suite of office applications.

Called IBM Lotus Symphony, the beta suite of tools for creating and sharing " documents, spreadsheets and presentations" is designed to offer Windows and Linux users an alternative to the pricey Office suite.

The suite is described as an enterprise-grade set of applications and is being positioned as suitable for consumers and businesses.

Symphony is based around the Openoffice.org suite of applications. IBM has been using the tools for some time but last week decided to throw its weight behind the drive for open source software by pledging free code, developers and resources to the Openoffice.org group.

Symphony is comprised of three core applications: Documents, Spreadsheets and Presentations, which IBM claimed can handle the majority of office-based tasks. The suite supports numerous file formats including Microsoft Office and Open Document Format (ODF), and also can output content in PDF format.

"IBM is committed to opening office desktop productivity applications just as we helped open enterprise computing with Linux," said Steve Mills, senior vice president and group executive, IBM Software Group. "The lifeblood of any organisation is contained in thousands of documents. With the Open Document Format, businesses can unlock their information, making it universally accessible on any platform and on the web in highly flexible ways."

IBM's support for ODF is an important part of the Symphony pitch, which promotes the use of open source formats, something Office does not do. In fact, the International Standards Organisation (ISO) recently dealt a blow to Microsoft's Office ambitions by refusing to endorse its Office Open XML format as an international standard for document exchange. ISO already endorses the widely used ODF.

The software suite can be downloaded here.