Opera works incredibly faster than Firefox on low-memory machines. I strongly second this. I recently tried Opera for the first time in ages on an old ThinkPad

Opera works incredibly faster than Firefox on low-memory machines. I strongly second this. I recently tried Opera for the first time in ages on an old ThinkPad ca. 2001 and it's astonishing what it can do with as little as 128MB of RAM and a Pentium 3. Where Firefox and Chrome struggle with even one tab and no extensions, I routinely find myself with a dozen or more open in Opera without it becoming even slightly sluggish. Whatever its faults, I'm extremely impressed.