At the beginning of this week, the CyanogenMod team provided an update regarding CM10.2 and their plans on CM11, based on Android 4.4 KitKat.  In their announcement, the team also mentioned that device maintainers have started releasing unofficial CM11 builds for getting a wider testing audience and feedback. Since then, unofficial CM11 builds have started popping up for a lot of Android devices. Below is a small list of all the devices, along with the link to their respective threads that I could find on XDA forums.

Nexus 5 Nexus 10 HTC One Nexus 4 Galaxy S4 (I9505) Galaxy Note Galaxy S3 (International) HTC EVO 4G LTE

Keep in mind that since this is among the early builds, most, if not all the features will be missing. Stability and performance will also be below par, but at least users will be able to get a taste of KitKat on their devices. Also note that not all of the above builds are from official CyanogenMod maintainers, but they are based on CM11 sources.