While I have been trying to make my desktop experience lighter, I somehow keep grabbing onto gnome-terminal; I guess it's what I've used to use and that I know how to configure with anti-aliased fonts etc. However, the fact that it is missing the ability to launch URIs from command line was hindering my dwm workflow, so I decided to do something about it.
First I tried to use different terminal, namely rxvt-unicode, which has the functionality, but couldn't configure it to my liking in reasonable time (freetype font spacing, mostly), I decided to see if I could hack gnome-terminal to do what I wanted.
At first I used a quite naïve method, just going the characters one by one (from end to start) and calling the VTE check method for each; and while it worked reasonably well it turned out to be terribly slow in some scenarios, with a single scan taking more than a second on a reasonably powerful laptop.
Since gnome-terminal stores the regexes also internally, it seemed like a good idea to try out if I could grab the whole contents of the terminal and run the regexes on it, and see if the results are faster. And indeed they were, but it yielded a slight bug with some uris being reported twice if they overlap. Lazy as I am, I chose to ignore this, and just go with it.
After finding the URIs, it was just a matter of drawing them somehow and handling the keypresses to launch them. I chose a very simple launching mechanism, resembling that of the vimperator/pentadactyl hints mode. Each hint is allocated a character from a set (after the set runs out, the URIs are ignored). Then I drew these hints over the terminal like they were tooltips, and voilà .
The resulting patch is 342 lines (226 lines added) and can be found from here. It should apply cleanly on top of gnome-terminal 3.6.2-0ubuntu1 (Ubuntu 14.10) and with fuzz on vanilla 3.6.2. Applying on top of master takes some handyman work.