Each widget is actually a separate process, which runs its own interpreter instance.

With the new Opera Widgets for Desktop we managed to break the dependency between widgets and the browser interface. From now on you don't have to have the Opera Browser open to run a widget. Furthermore, each widget runs in a separate process and integrates with the platform much better

New Opera Widgets for Desktop


A new platform allows Opera Widgets to move beyond the Web browser and onto your desktop. Multi-process architecture allows each widget to run as a separate process. Native OS integration now lets widgets behave like normal applications.

Opera is designed to restart and recover all your tabs if a crash occurs

Stability and resource-utilization improvements Put each document into an independent process (not thread: separate forked process) so that:

• When a document causes Firefox to crash, the whole browser won't be taken with it.
• When a bug in Firefox stomps on memory it doesn't own, other documents in memory are not corrupted.
• When a document causes Firefox to leak massive amounts of memory, closing that tab or window will free up the wasted memory.
• Memory fragmentation: If I open three documents, then close the second one, no memory is returned to the OS for other apps, because memory is only freed to the OS from the end of the heap. Also, however, I notice that if I open one document (and check the memory size), then open two more, then close the last two, the process size does not shrink back to what it was with only the first document (this looks like a memory leak). Putting each document into its own address space would solve these problems, because processes that terminate free all of their memory to the OS.
• When a bug in Firefox or a script on the page locks up (infinite loop or whatnot), the whole browser will not hang up