CyanogenMod is perhaps the most popular custom Android build out there today and consequently, it has been getting a constant flow of attention from developers, tinkerers and android-enthusiast all around.
The latest 12.1 version of the OS has finally made it out of the source code realm and on to actual device builds. So if your handset currently supports CyanogenMod 12, it is most likely updatable to 12.1, which is, in fact, based on the AOSP version of Android 5.1. This brings the popular custom ROM up to date, seeing how Android 5.1 is currently being seeded to Nexus devices, as well.
Even better yet, Cyanogen developers promise that the new version is directly installable over an existing CM 12.0 install, so no data loss should occur. There is a catch, though - all third party add-on zips must be manually updated to run properly. So the challenge is actually finding the proper, Android 5.1 compatible versions that don’t crash on the new OS.
On another CyanogenMod-related note, some of you might remember a recent scoop about a partnership between Microsoft and CM, boiling down to the integration of MS apps and services straight into the custom ROM. The whole story was quickly debunked, but Cyanogen took the liberty of reiterating this along with the new builds announcement. In the team's own words:
We are not bundling or pre-installing Microsoft (or any Cyanogen OS exclusive partner apps) into CyanogenMod.
So, with that fiasco officially out of the way, we can happily enjoy CM 12.1. But, if you do hop on the new version, let us just remind you, that it is a nightly build and as such, bugs of all caliber are expected. So, if you rely heavily on your CyanogenMod-powered device, you should probably wait for a more stable milestone build to pop up in the near future.
Also, the official download page for the custom ROM is currently down, so you might have to check back a bit later for the package.