Since its inception, OpenMRS' frontend has gone through multiple iterations. The two that you should know about are:
OpenMRS Reference Application 2 remains a widely-used version of the OpenMRS user interface. Multiple OpenMRS implementers have used Ref App 2 to create their own, customized distributions. This section contains all information related to Ref App 2 software interaction and user interface design, as well as user interviews, personas, etc.
OpenMRS 3, or "O3," is the next generation of OpenMRS. O3 uses modern technology and user interface design. To learn more about O3, how it is design-driven, and how to get started with O3 design, please go to our O3 project page.