The software tools aim to create a standardized way for cities all around world to measure their greenhouse gas emissions. With a common standard, cities would be able track the effectiveness of carbon-reduction programs.

The C40 summit of leaders from the world's major cities, which first met in London in 2005, was started with the aim of helping cities share ideas and band together to force down the price of technology to combat global warming.

Urban areas consume 75 percent of the world's energy and produce 80 percent of its greenhouse gas emissions.

"This new software tool will be an important resource in our work with cities around the world to fight global warming in practical, measurable and significant ways," Bruce Lindsey, chief executive of the Clinton Foundation, said in a statement.

Microsoft, the world's largest software maker, said it will provide the software and services for free and aims to have a product in place by the end of 2007.

Most of the technical details have not been finalized, but many of the tools would be Web-based and accessed through an Internet browser. They would incorporate features allowing cities to share data and effective policies.