I'm not sure if the bazaar really applies. In the bazaar you have a range of options and can pick and choose what suits you, but on the web we are seemingly stuck on a few base tools (html js, css) that have so much momentum that the will never go away. You don't get a restriction like that on the server or desktop side.
That's just the platform. If you look around the operating-system bazaar, you still have some basic notions that are shared among all of them (e.g. all their VFS look basically the same). That's the role fulfilled by HTML/JS/CSS: a hardware abstraction layer, if you will.
