Firefox, the browser that dared to challenge the supremacy of Microsoft's Internet Explorer, has just reached 400m downloads - and deservedly so. It now claims a market share of nearly 20% in the UK and 30% in Germany. Firefox, part of the admirable Mozilla Foundation, is based on open source, created and improved on by volunteers all over the world. The cooperative spirit that infused the open source movement is now taking over the world as people and corporations collaborate on music, videos, products or the Wikipedia. All of which makes it scandalous that the open source movement has not taken off in the UK as it has in other countries.