Ask HN: How do I get started with open source?

1. Filter projects by two criteria: do I know the stack? Am I a user? If you don't know the stack or aren't a user, you'll find the project to be inaccessible.

2a. Identify a bug or missing feature. You may do this yourself, or you may look at the issues list for the project. Fix the bug or add the feature.

2b. Or, if you prefer, you can write tests. Many projects have less than 100% test coverage, or their tests haven't been updated for the latest version. Writing tests for alpha or beta versions is really helpful in getting those versions finished.