Most of the helpers and extras on THREE.js have todo placeholders - DirectionalLightHelper for example http://threejs.org/docs/#Reference/Extras.Helpers/Directiona....

Just curious - as a contrary example, I would like to see links to a few OSS projects with exemplar documentation done "right". As an example, the Django project does a great job of treating its documentation as a "first-class citizen". While I have used OSS software and not developed, I would guess there are some good best practices / checklists out there for documentation (e.g. "what a good README should contain"; recommended tools to ensure documentation is easily contributable, versioned, and so on; "how to deploy this software", "how to install", architecture overview, "meta" documentation on how to contribute to the project, and so on). Would be good to see examples of those too. Thanks!

My understanding is that Docker has great documentation.

However, as a corporate sponsored project with multiple full time employees working on the documentation, it most likely fails your criteria in spirit.

Beets has great documentation:

http://beets.readthedocs.org/

Pgpool-II is a powerful piece of software that allows people to connection pool a Postgres cluster, and is even capable of managing a full multi master cluster. The docs are, however, so badly written and incomplete that it's way too hard to set up for most people. A shame, because it's great stuff.

Bucardo (http://bucardo.org/wiki/Bucardo) is a along the same lines. It could really use some help improving documentation.

OpenSSL: https://www.openssl.org/docs/

ssl(3): [STILL INCOMPLETE] Manual page documenting the OpenSSL SSL/TLS library.

I once added a few lines to Paperclip's README to promote a method I used from undocumented to documented. I thought it was a devious way to make them keep it around. :-) If you are looking for places to improve documentation, it's a nice selfish way to prioritize.

We have lots of features/tools/systems that need documentation https://github.com/jsdelivr/jsdelivr

Any help is appreciated

Documentation is a scratch an itch thing to some extent, so what interests you. If you want mentoring in documentation then look at FreeBSD which has a docs mentor program I believe.

Foreman could use some help - http://theforeman.org/ , contributions can be made to https://github.com/theforeman/theforeman.org

In particular, use cases that demonstrate its value proposition are lacking, API docs miss examples, and the manual has some outdated parts. The layout of the site is a bit dated too, but "it worked for us".

Apache Thrift http://thrift.apache.org/docs/ - A feature rich RPC framework with documentation that completely sucks. The docs page has evolved from "coming soon" over the last few months. You would have to dig deep into the library headers to find hidden "easter egg features".

Definitely doesn't need the most help, but there's been a call to action for helping write Rails docs for the 4.2 release: https://github.com/rails/rails/issues/16576

I'm going to give a niche one: VXL

http://vxl.sourceforge.net/

It's like OpenCV but much better written. The only trouble is there's almost no documentation or tutorials for beginners.

I think every single of them. the two I mostly care about are webrtc and bitcoin.

Hendrix can certainly use some help: https://github.com/hangarunderground/hendrix

oVirt is a great alternative to OpenStack, when it comes to managing virtual machines, unfortunately their docs are mostly outdated or too complex for non-devs: http://www.ovirt.org/Home

Pandas time-series library for Python is severely lacking good documentation!

ruby and/or rails