According to Jolla, you can now install Sailfish OS on your OnePlus One. OS is running an alpha build for the OnePlus One where the functionality is the same as when the OS was released for Nexus 5.
Known issues are as follow and these are some crucial functionality issues too:
- WiFi is not Working
- Camera is not working
- Android App Support is currently not supported .
- OTA Updates is also not supported
Here is a short video demonstration of the Sailfish OS running on the OnePlus One:
Check out the link in the source to know the instructions if you want to try the Sailfish OS on your OnePlus One.