Microsoft last night declared war on Linux and other alternative software that expose their basic instruction codes to public view, saying the "free software" movement poses a fundamental threat to commercial software and corporate intellectual property.

In an address at New York University, Mr Craig Mundie, senior vice president of the world's largest software company, contrasted the open product development approach of rivals with the careful "shared source" partnering approach favoured by Microsoft on its widely used Windows operating system.

Mr Mundie described the open software movement as "flimsy" and "flawed", jeopardising property rights and threatening to undermine the software industry, a key economic growth engine.