HTC has released the kernel sources of the European HTC One, along with the latest Droid DNA sources, as stated on HTC’s HTCDev Twitter profile:
The latest Droid DNA source is now available along with some variants of the HTC One. More to come!htcdev.com/devcenter/down…
— HTCdev (@htcdev) April 10, 2013
If you happen to have pre-ordered the gorgeous HTC One, or plan to buy one and want to play with the software of the smartphone, hit the link to the HTC Developer center to get the sources and start developing.