In 2012, under the username closeone, I worked on a Live CD for users of the HTC EVO 3D community to downgrade their bootloader from a more restricted version 1.50 to the previously exploited version 1.40 for a clean, full bootloader unlock using the Revolutionary S-OFF tool (now defunct). The CD was a TinyCore-based Linux distro with minimal extras. The GUI was built on top of Curses, and allowed for a novice computer user to be lead through the steps of downgrading their device without having to get their hands dirty with Linux commands. The CD was built around a brilliant Linux-only tool, developed by a guy known as Unknownforce. It was the de-facto way of achieving a full S-OFF unlock for a while, after an upgrade to the newer, more restrictive bootloader. The boot CD contained the tool, along with instructions, and a small handful of other useful software to aid the user after the downgrade.
The CD attained thousands of downloads while it was in its prime, and hundreds of success stories as well as some press (see blog) coverage.
Blog Coverage
XDA-Developers News (Archive Link)
Pocketables (Archive Link)
Other
If, by any stretch, you used the Live CD on your to downgrade your EVO 3D’s bootloader, and have come across this website, please send me an email here. I’d really like to hear from you.