[gmac]

It doesn't have to be contributing to existing open source projects. I always find it a bit surprising when other programmers have no code to show on Github or similar, for this reason: 1. most people who use computers day in, day out, encounter a pain point or two with the tools they use; 2. as a programmer, it seems natural to fix that pain point; 3. once fixed, it seems natural to share the fix, so that others are helped too (and that can also help post-hoc justify/rationalise the investment of time!).

[ptr]

You're forgetting the work that's needed to make it production (or at least more production) ready and the maintenance. A fix is often just made "good enough" for oneself in my experience. It's like sharing your dot files.

[rch]

I'm not even allowed to share my my custom portfiles. I started to, but was asked to hold off; that was 2 years ago.

[svisser]

Legal / contract constraints may prevent people from publishing code written at work or even in their free time.