Glossary HTC - bibanon/android-development-codex GitHub Wiki
HTC Android Specific Terms
RUU - ROM Update Utility. A program that flashes ROMs and updates to your phone. The official HTC-sanctioned method to update your phone.
RUU (on phone) - Software on the phone itself that works with the RUU on a computer to install ROMs.
hboot - The HTC bootloader for Android devices. Starts up your system and interfaces with fastboot and RUU flashes.
S-ON - Security ON; the default state of the bootloader. This makes it a bit harder to flash custom ROMs along with other security constraints..
S-OFF - Security OFF; the ideal state of the bootloader. This allows you to flash any custom ROM quite easily without having to jump through hoops.
HTCDev - A site made by HTC following developer protests that will allow users to unlock the bootloader on their phones. A big, but not complete victory, since it does not give S-OFF or root privileges, and permanently voids your warranty. At the very least, it always works.