Not long ago, I stumbled on a book about data science that piqued my interest. I found it on the O'Reilly site, which is a subscription based site that has tons of technical books, videos, and other learning material. I like the selection of material available on O'Reilly, but I don't really care for the apps they provide for customers to consume their products, so, instead, I convert their online books into ePubs so that I can read them offline, on my iPhone or iPad, when and however I like.
The book was written in 2015 by a guy named Jeroen Janssens from the Netherlands. He started the original edition while working on his PhD about half a dozen years ago. The central theme of his book is the intersection of data science and the use of command line tools. Because the state of tools has changed so much since his first publication, he embarked upon an effort to update it. The cool part is that he's doing this in an open source way, using GitHub to collect feedback from his intended audience. This is the part that intrigued me!
Early in the first chapter, I found a comment about Bash being the default shell for macOS. I suspected that this was dated material from the first edition of the book, when it would have been true, so I figured I'd submit a pull request (PR) to update that piece. I dug up some authoritative references, branched the first chapter, and whipped through a PR real quick. It was cool to think that I might have a small impact on this guy's new edition and that I could add some value that way.
As I thought a bit more on it, I wondered if there might be other areas that I could offer thoughts on. I recalled that when I read the first couple chapters there were some things that got in the way of reading for me. One was the way he did references - it appeared to be a combination of APA-like inline citations coupled with footnotes. The overall effect was a kludgy, referency-but-not-helpful injection of author and year parenthetical that bogged down the train of thought more so than it helped. It was here that I wondered about the possibility of making some kind of hyperlinked, pop-up info window that could be used to either provide definitions, or give basics on the reference material that supports the inline citation. I don't think these things exist in today's ePubs, but I'm not positive.