The latest platform numbers for Android versions have been released, and show KitKat continues to spread. It's up to 39.1% share of all Android devices from 33.9% last month. By comparison, the various Jelly Bean versions add up to 46%, down from 48.7% last month. Other versions, like Ice Cream Sandwich, Gingerbread, and Froyo, amount to under 15% combined.
You can see the rest of the numbers below. Sadly, Lollipop still isn't available widely enough to register as a blip on this chart, but hopefully we'll get a sense of the spread next month. What version of Android are you guys running currently?
Source: Google Developers