If you're a developer, testing your apps against the latest OS is a pretty crucial step in the process. Thankfully, BlackBerry has now released BlackBerry OS 10.3.0.700 and made it available for most devices although it does appear as though some versions may still be uploading to the developer download site.
If you're reading this and you're not a developer, then please consider this is NOT a full OS and while it might be cool to download and take for a spin it's missing some crucial portions so don't plan on using this as a 'daily driver' so to speak. You've been warned, that's all I can do.
That warning aside and knowing some will entirely ignore it, you can hit the links below to grab the OS for your specific device. I should note though, the servers are being hit pretty hard at the moment so maybe give it an hour or so and try then. Be sure to stop by the CrackBerry Forums to discuss more.