Tabs aren't threaded in Mozilla. All tabs are managed by a single thread, and are cooperatively multitasked. And it sucks, since for example, one webpage doing

Tabs aren't threaded in Mozilla. All tabs are managed by a single thread, and are cooperatively multitasked. And it sucks, since for example, one webpage doing a frequent setTimeout can adversely affect others. They've talked about moving to the Chrome model, but they don't seem to have the resources to do so in a timely manner. A lot of what their doing is catch up to Chrome. They sat around not really innovating in a way that's really meaningful to a normal user for a long time.