Own a Samsung Vibrant? Or, probably more correctly, recently pawned off a Samsung Vibrant to a relative and / or child, and want to make them hate it less? Good news! CyanogenMod 10.1 nightlies (based on Android 4.2 AOSP) are officially out for the Vibrant now, and you can get them at the CM website.
Definition: A "nightly" is a bleeding edge release that is built on a daily basis, usually at night after a full day's worth of new code has been committed.
It could oftentimes be unstable and not properly tested, lacking any changelogs, but eventually evolving into alphas, betas, release candidates, and finally stable releases.