Xiaomi has been one of the most active smartphone manufacturers this year. This company had introduced a ton of smartphones in 2016, ranging from their entry-level and mid-range Redmi-branded phones, to flagship Mi 5, MI 5s, Mi 5s Plus, Mi Note 2 and Mi MIX devices. That being said, most devices that the company introduced this year have one thing in common, they arrived with the company's MIUI 8 operating system, though some of them did ship with MIUI 7 initially.
In any case, Xiaomi had started pushing Android 6.0-based MIUI 8 OS to their devices a couple of months ago, and we also know that they've started developing MIUI 9 which will be based on Android 7.0 Nougat. The company had confirmed that the development process is on the way, and it seems like the company is currently looking for some alpha testers if you're interested, though not for MIUI 9, but Android 7.0-based MIUI 8. The company's MIUI builds can be quite confusing, some MIUI 8 builds are based on Android 5.1 Lollipop, while others are based on Android 6.0 Marshmallow. In any case, the company has some specific requirements if you're interested in becoming the company's alpha tester. In order to quality, you need to own the Xiaomi Mi 5, and on top of that, you do need to have a Chinese variant of MIUI installed on it, a global variant cannot be signed up, unfortunately, at least not yet, that option will become available starting next week. If you both of the Xiaomi Mi 5 and run Chinese MIUI variant on it, follow this link in order to become Xiaomi's alpha tester.
Now, in addition to all this, the company's MIUI Product Manager talked a bit more about MIUI 9. He said that the MIUI 9 will have a simpler UI compared to the MIUI 8, and that the company is working hard on improving both performance and power consumption in the new build of their Android-based operating system. Screen recording will come built into MIUI 9, which is also a nice addition by the company. We're still not sure when will the first MIUI 9 stable build become available, but chances are we'll wait for at least a couple of more months, we're only at the alpha stage of the development process, so… it will take a while.