There is no undocumented open source software, the documentation is just in a technical language. This is why learning to program is important, as it also means learning how to read the documentation.
I'm not being factious. We always say that documentation doesn't keep up and that the only real documentation is the code. Ultimately the only reliably documented software is free software.
I'm not being factious. We always say that documentation doesn't keep up and that the only real documentation is the code. Ultimately the only reliably documented software is free software.