Upstream Dependency Archetype
Characteristics: Intended as a building block for other software, so the user base is made up of developers, and adoption means third-party integration of your software into their products.
For smaller or more specialized libraries, this is a bit like Wide Open, but the experience for maintainers and contributors is qualitatively different. When a significant portion of the user base is able to participate technically, a lot of attention and investment may be needed from each serious participant just to take part in discussions, even when the number of parties in a discussion is small. Relative to Wide Open, there are fewer one-off or lightweight contributors and more ongoing, engaged contributors.
Therefore understanding who is using the project, and how, is key to knowing what goals the project can serve for Mozilla. An Upstream Dependency project can be quite influential thanks to its role in downstream dependees, even if only a small minority of developers in those dependees are familiar with it.
Examples: OpenSSL, WebKit
Licensing: Typically non-copyleft.
Community standards: Welcoming, and specifically amenable to one-time contributions.
Component coupling: Standalone, decoupled from one another and the downstream projects that pull them in.
Main benefits: Connections to many downstream dependee projects offers insight into market and usage trends, and can provide openings to potential partners.
Typical governance: Informal, maintainer-led, committer groups.