Cyanogen essentially shut down in December, and a blog post from CyanogenMod at the time said that for various reasons (including the “PR stain,” “shared sources,” and more), it would be shutting down as well. Now, CyanogenMod lives on in the form of LineageOS, and builds of the new Android-based operating system are now available for a select few devices.
Keeping version numbers from their most recent CyanogenMod releases (but named “lineage,” rather than “cm”), builds for the Nexus 6P, Nexus 5X, Nextbit Robin, Motorola Moto G4, and the Xiaomi Redmi 1S are now available at https://download.lineageos.org/. Each device has an “experimental” build (which will be updated weekly), as well as a nightly release.
If you’re a previous CyanogenMod user, you’ll want the “experimental” build, as Lineage says it should “allow you to ‘upgrade’ from CM to the signed LineageOS weekly”. The group notes, however, that this build will be “watermarked with an ugly banner” to make sure you don’t keep running this release and upgrade to a more stable “weekly” release later. In two months, these experimental builds will disappear.
While there may only be five devices available at the time of this writing, LineageOS is currently planned to support 80+ devices in the near future with stable weekly releases (including phones like the OnePlus 2 and OnePlus 3, as well as plenty of others). You can find the full list of devices that will soon get Lineage, as well as how to install already available builds, over at their website.
Update: LineageOS is now available for the OnePlus One as well.