It's hard to know what codebases will last 20 years. But I think even if an open source software project becomes less relevant over time, hopefully the things o

It's hard to know what codebases will last 20 years. But I think even if an open source software project becomes less relevant over time, hopefully the things one learns about software construction and building sustainable open source communities to other projects in the future. One of my personal goals for Zulip (https://github.com/zulip/zulip/#readme https://github.com/zulip/zulip/#readme) is for it to be a teaching-quality codebase. This entails a lot of decisions about how Zulip is designed and how we as a community collaborate on it. But above all, it entails a focus on constantly trying to debug and fix barriers to new contributors joining the project, in addition to investing in things like readability, well-designed test suites, documentation for contributors, etc. I'd look for those attributes in a project.