NumPy [0] and matplotlib [1] both have well designed tutorials, specific function documentation, and integration with IDEs for Intellisense help while programming.

[0] https://docs.scipy.org/doc/numpy-1.12.0 [1] https://matplotlib.org/contents.html

PostgreSQL has very thorough and well-written documentation.

I really like the way (most of) PHP is documented. Every function gets a page, most of those pages get usage, examples and comments. However, when you go into some of the more obscure stuff, the documentation tends to just be function prototypes. So not perfect but I really enjoy it.

SQLAlchemy docs are very good. I remember having to drop two layers of abstraction under the main API to get some very specific stuff done and it was still documented with useful example code.

The actual software design is great as well, single-handedly changed my mind about ORMs.

I think TeX came pretty close.

I think the Exim spec is pretty much the gold standard for reference documentation, but they need a separate user-friendly introduction too (there was a separate paper book at one point).

Laravel is always praised for its documentation: https://laravel.com/docs/

I've heard that every comment in code follows the same pattern: every line becomes smaller and smaller. There is a lot of dedication in this project.

This beautiful-docs repo has a list of higher quaility docs...

https://github.com/PharkMillups/beautiful-docs

If this wasn't sarcastic, it probably should have been.

There is no perfect documentation, because you can't predict your audience. I document code in such a way as to make it easier for myself to go back to it. I've kicked myself too many times to count where I didn't document something; went back to code, found it confusing, went to find out who wrote it only to discover it was me.

Document your code for yourself.

RabbitMQ, very easy to start in any language you'd want.