Good news for developers that are interested in working with the development on the upcoming HTC One M9 devices, HTC has just dropped the source kernels for the HTC One M9 over on their HTC Dev portal website. As these are source files meant for development work for various different things, none of the software files will do end users much good. At least not up front. It can however, benefit end users in the long run as the source files and kernels can help developers to improve stability with apps and other software on the device, as well as use the files for development of custom ROMs, and custom Kernels, which will be usable by regular end users down the line.
All of the source kernels amount to roughly around 500MB of file size each (517MB to be exact) and are based on the Android 5.0.1 software build which is what the HTC One M9 is shipping with out of the box. It's also worth noting that as of right now HTC has not posted any source kernels for the US model HTC One M9, so any U.S. based developers won't have any use for the stuff that's currently available unless they're working specifically with one of the models for the regions that software has been posted for.
At the moment HTC has posted the source kernels for models in various different regions, which includes the EU unlocked model, the ES model on Orange, as well as various other models from Asia, France, Taiwan, the UK and others. If you happen to be a developer using any of the models from the U.S. carriers, a quick bookmark of the page which we have linked below would be advantageous to make it easy to jump back to at a later date when HTC releases the source kernels for those versions.