![firefox 3.7](http://www.netupd8.com/w8img/n6by9u_th.jpg)
To enable it, type about:config in the address bar, and set:
dom.ipc.plugins.enabled
to true.
![firefox multi-process](http://www.netupd8.com/w8img/t0iv40.jpg)
Please note that even though "dom.ipc.plugins.enabled" exists (and I've enabled it) in the latest Firefox 3.7 Linux build, I couldn't find a second Firefox process, so this is probably only available for Windows right now.
[via downloadsquad]