Mentioned a few times in recent months on Phoronix has been SDDM, a lightweight Qt/QML-based display manager. The good news now is that the Simple Desktop Display Manager has seen its first official release.
The first release, Simple Desktop Display Manager 0.1.0, was shared via Google+ to the world. As talked about in earlier articles on SDDM, it's a lightweight yet modern display manager that uses Qt and Qt Quick for making a very configurable display manager that is very lightweight and opens up lots of possibilites. The only har dependencies on SDDM are PAM, XCB, and Qt. In its months of development, it's been quick to get new features.