## Markdown vs reStructuredText for teaching materials

Featured image: Brandi Redd | Unsplash (photo)

Back in summer 2017. I wrote an article explaining why we used Sphinx and reStructuredText for producing teaching materials and not a wiki. In addition to recommending Sphinx as the solution to use, it was general praise for generating static HTML files from Markdown or reStructuredText.

This summer I made the conversion of teaching materials from reStructuredText to Markdown. Unfortunately, the automated conversion using Pandoc didn’t quite produce the result I wanted so I ended up cooking my own Python script that converted the specific dialect of reStructuredText that was used for writing the contents of lab.miletic.net and fixing a myriad of inconsistencies in writing style that accumulated over the years.

## reStructuredText as the obvious choice for the software documentation

I personally preferred to write reStructuredText, which I found to be more powerful and better standardized than Markdown (I have heard the same is true about AsciiDoc though I haven’t personally used it). When we forked rDock to start RxDock, reStructuredText and Sphinx were the obvious choices for its documentation. A good argumentation why would a software developer prefer reStructuredText over Markdown for software documentation is given in a very fine article written by Victor Zverovich. He mentions two main advantages, the first one being:

reStructuredText provides standard extension mechanisms called directives and roles which make all the difference. For example, you can use the math role to write a mathematical equation (…) and it will be rendered nicely both in HTML using a Javascript library such as MathJax and in PDF via LaTeX or directly. With Markdown you’ll probably have to use MathJax and HTML to PDF conversion which is suboptimal or something like Pandoc to convert to another format first.

(For what it’s worth, this has now been addressed by PyMdown Extension Arithmatex, which is easy to enable when using MkDocs with Material theme.)

The second advantage mentioned by Zverovich is very useful for software documentation and a feature that would be only nice to have elsewhere:

In addition to this, Sphinx provides a set of roles and directives for different language constructs, for example, :py:class: for a Python class or :cpp:enum: for a C++ enum. This is very important because it adds semantics to otherwise purely presentational markup (…)

## Markdown as the obvious choice elsewhere

Despite recommending reStructuredText for software documentation, Victor opens his blog post with:

In fact, I’m writing this blog post in Markdown.

It’s the obvious choice for blogs hosted on GitHub Pages since it offers the Markdown to HTML conversion using Jekyll. You don’t have to care how the conversion is done so you can worry about writing the contents. However, the same feature isn’t available for reStructuredText and AsciiDoc as Jekyll supports neither of the two.

Is GitLab any different from GitHub? GitLab Pages supports almost anything you can imagine thanks to GitLab CI/CD, including Sphinx. However, the same isn’t the case for project wikis where GitLab supports Markdown and AsciiDoc, but not reStructuredText (it has been requested 5 years ago).

And it’s a similar story elsewhere. Reddit? Markdown. Slack and Mattermost? Both Markdown. Visual Studio Code supports Markdown without any extensions (but there are 795 of them available if you feel that something you require is not there, compared to 21 for reStructuredText). Finally, it’s a very popular choice among my colleagues and students, which is expected as there is nothing like HackMD for reStructuredText or AsciiDoc that I know of.

Obviously, many of these tools weren’t around when we switched to Sphinx back in 2014. However, now that they are here to stay, Markdown is starting to look like a better choice among the two.

## Moving from reStructuredText to Markdown for teaching materials

In my particular case, the straw that broke the camel’s back and made me decide to convert the teaching materials from reStructuredText to Markdown was the student contribution of ZeroMQ exercises for the Distributed systems course (not included yet). I asked the student to write reStructuredText, but got the materials in Markdown and I can understand why is that. Let’s say that the student wanted to do things properly in reStructedText and Sphinx. The procedure is this:

1. Git clone the repository.
2. Open the folder in your favorite editor, say VS Code, notice it doesn’t highlight rST out of the box, no problem there is the extension, right?
3. Install the reStructuredText extension (homepage), close all NotImplemented exception notes that appear when opening the project.
4. Open a file just the get the feeling of how rST should look. Try to preview it. Unknown directive type “sectionauthor”. Never mind, it’s just one command that is unsupported.
5. The source code blocks aren’t highlighted neither in the edit nor in the preview pane. Oh well, it’s not a show stopper.
6. Well, there are more errors in the preview. Never mind, the compile is the real preview. Let’s compile things every time something is changed.
7. (…)
8. Send the changes by e-mail or git add, git commit, and git push.

Compare that with the Markdown workflow:

1. Git clone the repository.
2. Open the folder in VS Code and start writing.
3. Send the changes by e-mail or git add, git commit, and git push.

To be fair, VS Code Markdown preview is not rendering Admonitions, but that’s how it goes with the language extensions. Still, it’s much easier to get started with Markdown and MkDocs than with reStructuredText and Sphinx if you are new to documentation writing, which is the case with most of the students.

There are a number of other things I like:

• Material theme for MkDocs is awesome. It’s a set of extensions in addition to a good looking theme.
• Integrated search is designed as “find as you type” and provides a much better user experience.
• Much faster building. It takes 11 seconds to build the group website with MkDocs, while it took 37 seconds to build the older version of the same website with Sphinx.
• Builtin GitHub Pages deployment functionality. It’s possible to do the same with Sphinx, but it’s much nicer to have it builtin and maintained.
• Automatic building of the sitemap. (There’s an extension for Sphinx that does the same.)

Overall, I am very satisfied with the results and I’m looking forward to using Markdown for writing teaching materials in the future. I’ll continue to write RxDock documentation in reStructuredText since fancy cross-references and numbered equation blocks are very easy to do in reStructuredText. In addition, there is an official way to produce PDF output via LaTeX, which is quite important to have for proper scientific software documentation. Also, the potential contributors, in this case, are somewhat experienced with documentation tools and can usually find their way around with reStructuredText and Sphinx so it’s not that much of an issue.

## Why use reStructuredText and Sphinx static site generator for maintaining teaching materials

Featured image: Les Anderson | Unsplash (photo)

Yesterday I was asked by Edvin Močibob, a friend and a former student teaching assistant of mine, the following question:

You seem to be using Sphinx for your teaching materials, right? As far as I can see, it doesn’t have an online WYSIWYG editor. I would be interested in comparison of your solution with e.g. MediaWiki.

While the advantages and disadvantages of static site generators when compared to content management systems have been written about and discussed already, I will outline our reasons for the choice of Sphinx below. Many of the points have probably already been presented elsewhere.

## Starting with MoinMoin

Teaching materials for the courses some of my colleagues and I used to teach at InfUniRi and RiTeh, including laboratory exercises for the Computer Networks 2 course developed during early 2012, were initially put online using MoinMoin. I personally liked MoinMoin because it used flat text files and required no database and also because it was Python-based and I happen to know Python better than PHP.

During the summer of 2014, the decision was made to replace MoinMoin with something better because version 1.9 was lacking features compared to MediaWiki and also evolving slowly. Most of the development effort was put in MoinMoin version 2.0, which, quite unfortunately, still isn’t released as of 2017. My colleagues and I especially cared about mobile device support (we wanted responsive design), as it was requested by students quite often and, by that time, every other relevant actor on the internet had it.

## The search for alternatives begins

DokuWiki was a nice alternative and it offered responsive design, but I wasn’t particularly impressed by it and was also slightly worried it might go the way of MoinMoin (as of 2017, this does not seem to be the case). It also used a custom markup/syntax, while I would have much preferred something Markdown/reStructuredText-based.

We really wanted to go open with the teaching materials and release them under a Creative Commons license. Legally, that can be done with any wiki or similar software. Ideally, however, a user should not be tied to your running instance of the materials to contribute improvements and should not be required to invest a lot of effort to set up a personal instance where changes can be made.

MediaWiki was another option. Thanks to Wikipedia, MediaWiki’s markup is widely understood, and WYSIWYG editor was at the time being created.

In an unrelated sequence of events I have set up a MediaWiki instance in BioSFLab (where I also participated in research projects for almost two years) and can say that setting up such an instance presents a number of challenges:

When migrating a MediaWiki instance from a server to another server, you have to dump/restore the database and adjust the config files (if you’re lucky it won’t be required to convert Apache configuration directives to Nginx ones or vice versa). None of this is especially complicated, but it’s extra work compared to flat file wikis and static websites.

Finally, my favorite MediaWiki theme (skin in its terminology) is Vector, so my potential wiki with teaching materials would look exactly like Wikipedia. While nice and trendy, it is not very original to look like Wikipedia.

## Going static, going reStructured

Therefore, we opted to use Sphinx and reStructuredText, as it was and still is a more powerful format than Markdown. We specifically cared about the built-in admonitions, which made it easier for us to convert the existing contents (Python socket module lecture is a decent example). The advantages of Sphinx were and still are the following:

There is a number of issues which affected us:

• the time to deployment after the change: varies depending on the change, but it’s in the order of tens of seconds in the worst case,
• the need to automate the deployment upon git push (note that this does not increase attack surface, since git uses SSH or HTTPS for authentication and transfer).
• learning curve to add content: MediaWiki’s WYSIWYG editor beats using git and reStructuredText in terms of simplicity.

## Conclusion

A rule of thumb here would be:

• if many people inside of an organization are going to edit content a lot and the content is more like notes than a proper documentation, then MediaWiki (or DokuWiki) is the choice,
• if the content has an obvious hierarchy of parts, chapters, sections etc. and/or it is evolving like a piece documentation changes with software it documents, then Sphinx (or any of Markdown-based generators, e.g. HotDoc or MkDocs) will do a better job.