New features on Read The Docs

Since the Django Dash ended, We’ve been working on adding some requested new features to Read The Docs. There are a couple of major ones that we have added that I’d like to talk about.

hg and svn support

We’ve added support for all of the version control systems that people have requested. When you sign up or edit a project, you can now tell us which VCS you are using, and we’ll use that to check out your code to build your documentation.

There are two libraries that I wish existed: One to smartly parse urls into the correct repository, and a standard VCS abstraction that lets me treat all VCS’ as the same. These would integrated presumably, so I could do vcs clone <url> and vcs update, and it would “Just Work”

Whitelisting support

By default we don’t execute any python code when you import your project. This is a security precaution that we take, so that means disabling all extensions by default. A lot of people are using autodoc and some other extensions, so we have added the ability to whitelist projects so that they are built without any sanitization on our part.

Subdomain and CNAME support

This is a really exciting one for me, because I’ve been learning more and more about sysadminery lately, and this was a fun little mixing of the two. For any project, you can now access the projects documentation at <slug>, for example, pip’s documentation is now at

Now that we have subdomain support, this makes supporting CNAME’s really simple. So if you have your own domain name, and you’d like those docs to point to us, it’s simple. All you need to do is add a CNAME record for that domain in your DNS settings to point at your subdomain URL. Pip is another good example here, now is hosted on RTD. Other notable examples are and :)

All of this support is implemented in middleware and only ends up being about 25 lines of code. There are going to be some complications when we try to add multiple version support, and internationalization, as you can’t really specify those well on subdomains. I see us having a “default” project version, as well as letting you have other versions hosted as well.

“RTFM” is a well known term in the programming community. Luckily when we were scheming up names for our project, we noticed that was available. We went ahead and bought it, and now we’re supporting <slug> and<slug> redirects that go to your RTD page. This is a nice little keystroke saver, as well as a fun was to refer people to your documentation. This is implemented simple in an Nginx server directive. I’m sure it can be improved upon, but it’s working well at the moment.

I think adding the ability to have “smart slugs” here would be interesting, so it could actually perform a search or something, and return the top result, kinda like LMGTFY. This could be a neat feature to add on.

LaTeX support

LaTeX is a pain to get setup, so if you want to support rendering LaTeX, we now support that as well. The sympy has been testing their docs on RTD, and have helped me clean up a bunch of bugs. The Geometric Algebra section shows off some of the LaTeX goodness.

* Update:* Just for kicks, we currently have 120 users and 80 projects currently hosted on Read The Docs. At least a couple of these are using RTD as their official documentation host. I’m pretty happy with the uptake that’s already happened in the last 2 weeks (wow, that little?!). Thanks everyone for checking it out!

* Update 2* We also have a new IRC channel if you need help or have questions, it’s #rtd on

Hey there! I'm Eric and I work on communities in the world of software documentation. Feel free to email me if you have comments on this post!