If you're rooted and love to flash new ROMs, you may want to check out the first non-nightly release of CM13 from the CyanogenMod team. Initially, this release will be available for around 40 different devices, and the team is still working on pushing for more.
Depending on your current usage and state of your phone, you may need to follow some different instructions for flashing this build. From the CyanogenMod post:
We left the M release builds in the oven longer than we thought, but nothing a little graham cracker and chocolate can't make that much better. CM13.0 brings Android 6.0.1 (r17) goodies such as the battery saving 'doze' functionality and new permissions model, alongside the CM features you'd expect.
This is the first non-nightly release for CM13, which means this will the first step many of you take into the world of Marshmallow. M brings along a handful of items that will pose issues if you are caught unaware, so in the interest of saving you some potential heartburn, we're going to highlight that there are a couple of different update scenarios applicable.
If you are looking for something new to try, or have been waiting for a CM13 release to flash, now is your chance. Be sure to check out all the instructions, and remember to be careful while flashing your phones!