In addition to several other releases, Apple on Monday pushed out the third developer beta of OS X 10.11.4. The update is available either via the Updates tab of the Mac App Store for current 10.11.4 testers, or on Apple's developer website as a standalone download.
Today's beta 3 comes two weeks after beta 2 and nearly a month after the original version of 10.11.4 was released. The update is mostly under-the-hood improvements, but it does include a few new features such as support for Live Photos and password-protected Notes.