HTC test interface Sense for devices from other brands
HTC is going to test its Sense interface for devices from other brands. The manufacturer will let you know via an email to people who have signed up to test new HTC software. It is probably a launcher and not a firmware.
For the test, HTC requires a non-HTC phone with Android 4.4 or higher, reports tweaker TNE, who received the email from the manufacturer. The email comes from HTC Preview, a program from HTC that distributes test versions of software for experimentation and bug detection.
HTC refers to the software as Sense Home 8 beta, which presumably concerns the launcher as it is on the HTC 10. In addition to standard home screens and an app drawer, it also contains a version with ‘free layout’. Then you can add ‘stickers’, general images that you can move freely over the image. You can add any shortcut you want to that. Then you can also omit the labels, creating a home screen, apparently without shortcuts.
It is not yet known exactly, but given the requirements it is not a whole custom rom with Sense. That would require users to have an unlocked bootloader or otherwise flash another ROM.
It is unusual for a manufacturer to release its launcher for competitor devices. HTC will not be the first to release it, however, because Asus already did it and Xiaomi had a Miui launcher until a few years ago. Also, there are many third party launchers for Android like Nova Launcher and Action Launcher.