JPearce Project Evaluation
I would rate OpenMRS on size/scale/complexity as a two because the codebase is large, but they are definitely beginner-friendly. I would rate it as very active given the number and frequency of commits.
I would also consider it popular with 4.2 Stars and 3,719 Downloads this week. The number of downloads per day ranges from 300 to more than 600. 75,090 in the past year.
The community appears very friendly and welcoming. It does look like a good community.
In terms of Mission Critical Criteria-Approachability, OpenMRS seems 3-Ideal-Obvious link to get started and detailed instructions. The approachability also seems excellent. Mission Critical Criteria-Suitability. The system dashboard shows 39 curated introductory tickets, including bugs, new features, and improvements. There are 71 items listed in the introductory area and many more tracked in JURA tickets.
The number of bugs suitable for students to tackle is high and the information on the process of how to submit bug fixes is clear. Whether it could work in CS1 is less clear to me--I would need to spend more time really thinking about this question specifically.
The IRC logs show chats from an hour ago and earlier today. Operating Processes seem moderately well-documented. I can't readily find the links to information about coding standards, but the links to the the code submission process, and commit privileges are on the How-To Submit Code page. Posts in the discussion forum do seem to receive timely and supportive responses. Newcomers clearly get strong support.
For a course about contributing to Open Source, this seems like a great project.