Apple's first big iOS 6 update is one step closer to a public release.

Today the company quietly released the third beta version of iOS 6.1 to developers, another step on the way to sending it out as an update to the general public.

Today's update, which includes "bug fixes and other improvements," comes 21 days after the last beta.

All three beta versions, made available to developers for testing ahead of a public release, have been light on major new additions to the software. Apple typically saves such additions for major releases, but has historically added some new features along the way. So far, the list for iOS 6.1 includes new boarding pass behavior in Apple's Passbook software, tweaks to Safari, and a back-end change in Apple's mapping software.

Apple's last update to iOS 6 was iOS 6.0.1 on November 1. That software fixed a handful of bugs, including one that kept iPhone 5 users from installing over-the-air software updates. It also fixed an issue with lines appearing on the software keyboard, and a bug that deleted meetings from calendars when accepting an invitation.