CyanogenMod

The Cyanogen team stated that there would be "something special" in store for the new year, which as it turns out is the announcement of nightly builds of CyanogenMod 12, which is based on Android 5.0.1 Lollipop. The first rollout of CM12 nightlies is set to commence soon, although the team notes that work on the M release (milestone snapshot, more stable than a nightly but potentially some issues) is 85 percent complete as of now.

As such, features like the theme engine, quick settings ribbon mode, customizations to the navigation bar, sound panel and quick settings as well as quick unlock are left out of the nightly builds, but should be available over the coming weeks as the team adds more features to the release. Cyanogen is also working on a slew of new features, as noted below:

CM11 features aren't the only thing we're working on, with new features such as Ambient display, a brand new Messaging app, and some small tweaks including a weather option in the new Lollipop extended status bar. Our team is continuing to work on new additions and we have some big plans ahead for L.

To check if the CM12 nightly build is available for your device, head here. Do note that there will be bugs considering that this is a nightly build. As for now, the CyanogenMod blog states that the Android Lollipop-based build is available for 31 devices, with more being added on a daily basis. Check out the link below for instructions on flashing CM12 and the caveats that apply.

Source: CyanogenMod Blog