Hot out of the oven is leaked OS for BlackBerry 10 users. This OS sitting in at 10.2.1.2947 and is available for all devices. Unfortunately for users with a Z10 with an STL100-1 model, this isn’t available for you.
This OS comes in the form of Debrick BARs and Upgrade. If you want to load this without losing any of your information, you might want to download the Upgrade BAR and if you fancy a clean installation, download the Debrick. However, the Upgrade BAR doesn’t include any of the updated apps/files that are present in the Debrick BAR, so you might want to download the Debrick and extract the BAR files out of it. I wrote an extensive guide on how to load a BlackBerry 10 OS onto your phone if you’re having any problems. Autoloaders are also included too.