A Downing Street petition is calling for the UK government to drop Microsoft's Internet Explorer 6 (IE6) and move to a more modern browser.
The petition says that IE6 has security flaws and uses outdated technology, creating a burden for developers.
The petition comes as the Department of Health advised the NHS to move away from the old browser.
Other government departments - and many firms - still use the software, which was first released in 2001.
"Most creative and software development companies are forced by government department clients to build websites for IE6 when most of the industry has moved on," the petition reads.
A campaign in the US, called ie6nomore, is supported by more than 70 web firms and claims the software is "holding the web back".