In addition, a number of you apparently rename your TenFourFox builds to just TenFourFox.app, so this version will try that filename if the proper machine architecture is not found. If you really can't control for that either, make a copy of the browser as TenFourFoxBoxRunner.app and it will take precedence over any other executable (but remember to keep that copy up to date!).
Finally, there were also several requests for allowing URLs to be sent back or at least copied for the main browser's benefit. I'm weighing my options on how to push the URL through (Launch Services or otherwise), but you can at least now go to the Box menu and copy the current location URL to the clipboard, or right-click any link to do the same, which you can then paste into your browser of choice. Localization is still not yet supported because we're not yet to a string-freeze point, but we're getting close.
Remember to stop all foxboxes before you upgrade them, and make sure TenFourFox is still running before you start them back up if you want to have the main browser running parallel. Developers, look at the Makefile in the Things To Try: For Developers folder for how to automate foxbox creation and upgrades from the command line.
As of this release, TenFourFoxBox has an official home page and download site and you can grab 1.0 from there. Assuming no major issues by the end of this week, we'll start publicly rolling it out, and then I'll start the arduous trek towards TenFourFox 45. Meanwhile, for 38.6, there will be some updates to the font blacklist but so far no major bugs yet.