I’ve complained before about Firefox not supporting split view and encouraged readers to vote for Bug 231156. I just learned from the bug this morning that Firefox has a few extensions to give you this very thing. The one that I like the best is Split Browser, which took the approach that the “split” should be at the browser level (across all tabs) rather than at the per-tab/document level (which I would have originally preferred). I think the choice makes some sense, because that way you can compare two different documents as well as two regions of the same document.
I also wish it had the little scroll-bar splitter that is present in so many Microsoft Office applications. But right-clicking and choosing Split isn’t so bad for those rare cases where I want to compare two sections of a loooong web page. All in all, I’m pretty happy with Split Browser though…
theres always conkeror and C-x-2