CyanogenMod has changed a lot over the years, but we're still seeing custom ROMs pumped out. The 12.1 release is the latest one to go stable. It offers users the ability to run Android 5.1.1, IMAP idle support, and SDK v1.
CyanogenMod has also pushed out new stable builds for versions 11.0 and 12.0. These are security releases that address a number of security issues, including Stagefright. Get the update not for new features but to make sure that your phone or tablet is safe.
Builds are only available for devices where maintainers have marked builds as 'Good to go.' So if the gadget you're holding isn't yet on the list, you will have to be patient or opt to install one of the pre-release builds instead. Check the CyanogenMod Downloads page to be sure.