[thejosh]

The best opensource projects that you'll stay interested in the medium-long term are projects you actively use. Anything else you'll get bored of.

[gadflyinyoureye]

The same is true of a encyclopedia. If you try to read it directly, word after word, it is boring. However, if you treat it as a reference, as the OP is asking for in Go code, it can be helpful and possibly inspiring.

[LudwigNagasena]

Library code is usually quite different from app code.