Following the release of iOS 9.3 beta 2 and tvOS 9.2 beta 2, Apple has also seeded the second beta of OS X 10.11.4 update to developers for testing purposes, two weeks after seeding the first OS X 10.11.4 beta and a week after releasing OS X 10.11.3.
OS X 10.11.4 includes a couple of new features, such as the ability to support password protected notes in the Notes app, but like the recent OS X 10.11.3 update, it appears to focus primarily on under-the-hood bug fixes and performance improvements with few noticeable outward-facing changes.
The second OS X 10.11.4 beta can be downloaded through the Apple Developer Center or via the Software Update Mechanism in the Mac App Store.
We will update this post as new features are uncovered, if any.
Apple seeds OS X 10.11.4 El Capitan beta 2 to Developers