Alpha version of custom Android 5.0 ROM available now for OnePlus One owners2
Recently, OnePlus hinted that it was working on its own build of Android that is close to being stock. An alpha version of the Android 5.0 build is available for OnePlus One users now to flash on their phone. The process calls for TWRP custom recovery to be installed on the handset, along with a ZIP file containing GApps. The latter includes Google's apps and software like the Play Store and Gmail. You can find everything you need, including instructions, at the sourcelink. You should back up all of your data prior to starting this process. And there is the chance that you might brick your phone, so tread carefully.
As for OnePlus' future plans, no one knows whether this Android build will eventually be sent OTA to just Indian OnePlus One models to fulfill the expected ruling from the Indian court, or if it will be deployed globally as well. OnePlus says that its custom Android ROM will be bloat-free "with stock-Android-like simplicity by default."
source: OnePlus via AndroidPolice