IBM, which recently launched a combination of its Lotus software and cloud-based services with Canonical's Ubuntu Linux, said that it hopes to lure users away from Windows 7 with the promise of a cheaper and more efficient package.
The company said that its Client for Smart Work platform avoids the need for expensive software and the hardware updates that older systems may require.
"If a company is a 'Windows shop', at some point it will need to evaluate the significant costs of migrating its base to Microsoft's next desktop," said Bob Picciano, IBM general manager for Lotus.
"Our goal is to help organisations free up desktop expenses to use in more strategic collaboration and business transformation projects."
Software-as-a-service pioneer Salesforce.com also took a shot at Microsoft, suggesting that Windows 7 was merely an effort to keep pace with more sophisticated cloud-based platforms.
"When the world's largest software company markets its flagship product as 'more stable', you know that there is something terribly wrong with the state of innovation at Microsoft," said Bruce Francis, vice president of corporate strategy at Salesforce.com, in a statement.
"The truth is that the world has moved on to cloud apps for consumers and businesses, and cloud platforms for developing new services."
The comments could indicate that competitors are sensing blood in the water following the troubles of Windows Vista. Apple has already said that it expects to gain customers with the release of Windows 7.