Joe Corneli, of of the contributors, mentions this in a cool-sounding "Peeragogy" context at metameso.org/~joe/:
I earned my doctorate at The Open University in Milton Keynes, with a thesis focused on peer produced support for peer learning in the mathematics domain. The main case study was planetmath.org; the ideas also informed the development of “Peeragogy”.
Thus OurBigBook.com.
Generally, if something is labelled as "e-learning", it's not a good sign, as it implies that it adheres to the "teacher"/"student" separation which Ciro Santilli much despises: E-learning websites must allow students to create learning content.
Ciro Santilli does the same via Google searches and Twitter/Reddit searches for himself, you can't invent anything new nowadays:
Kibo was known for his high-volume but thoughtful posts, but achieved Usenet celebrity circa 1991 by writing a small script to grep his entire Usenet feed for instances of his name, and then answering personally whenever and wherever he was mentioned, giving the illusion that he was personally reading the entire feed.
- webapps.stackexchange.com/questions/145817/on-which-country-are-the-creators-and-servers-of-archive-today-archive-is-base/175600#175600 by Ciro Santilli
Points to:"Alex Conferno" is also brought up: twitter.com/conferno - www.reddit.com/r/COPYRIGHT/comments/1bcqf3y/archivetoday_archiveis_copyright_victims/
- drive.google.com/file/d/1JTPVd09NPaGH-KzGv2jU3XXcFiJAoUjw/view some crazy due investigating, let's see how long until it goes down, posted at:
- www.reddit.com/r/DataHoarder/comments/12trawt/has_anyone_ever_actually_spoken_to_denis_petrov/
- gyrovague.com/2023/08/05/archive-today-on-the-trail-of-the-mysterious-guerrilla-archivist-of-the-internet/. Trended on Hacker News: news.ycombinator.com/item?id=37009598
- gigazine.net/gsc_news/en/20240326-archive-today/
Other mentions of "Denis Petrov":
In 2025, the FBI got interested in the creator of the website due to its news paywall circumvention usage, and the dude started going nuts, coming after anyone who had previously investigated him with OSINT, e.g. the author of gyrovague.com and Ciro Santilli:
Later on in 2026 Wikipedia banned archive.today links because it had DDoS'ed Wikipedia and tampered with snapshots: arstechnica.com/tech-policy/2026/02/wikipedia-bans-archive-today-after-site-executed-ddos-and-altered-web-captures/ The dude had gone completely unhinged, destroying everything he built.
- archive.org/post/1055220/how-to-query-for-all-the-websites-that-end-in-combr
- archive.org/details/WebArchiveDomainFiles only a random list with per-ccTLDs upon request of (paid presumably) partners. As of 2023 only contains the Netherlands: archive.org/details/Dotnl-2016-present-domains-in-wayback-domainyear-of-last-capture
Some people have been creating YouTube channels that just post and go over a large number of Stack Exchange questions, some of them with a quick random intro video. Perfectly legal due to CC BY-SA but really weird stuff!
- Roel Van de Paar www.youtube.com/@RoelVandePaar. This one seems to be the OG. As of June 2024 it had 2M videos (!), 161K subscribers and only 47M views. youtube.fandom.com/wiki/Roel_Van_de_Paar mentions "he has the highest number of uploads of any YouTube channel". Interestingly at www.linkedin.com/in/roelvandepaar/?originalSubdomain=au he says he is a test engineer at MariaDB.
- Peter Schneider www.youtube.com/@peterschneiderQandA e.g. www.youtube.com/watch?v=GBQhrKRpUdI "How to put a newline special character into a file using the echo command and redirection operator?" from unix.stackexchange.com/questions/191694/how-to-put-a-newline-special-character-into-a-file-using-the-echo-command-and-re)Stackexchange
- Sophia Wagner www.youtube.com/@SophiaWagnerQandA. As of June 2024 it had 14k videos and only 88k views, so she made 88 bucks on it.
- E.g. www.youtube.com/watch?v=elIlkJneVBI "Vertically stack multiple images using ImageMagick" goes over superuser.com/questions/290656/vertically-stack-multiple-images-using-imagemagick
- www.youtube.com/@LukeChaffeyTechInfo Luke Chaffey, an Indian-American dude, e.g. www.youtube.com/watch?v=wmx6mN_G83s "Do Boost Geometry nearest queries always sort results ordered by smallest distance first?"
- www.youtube.com/@pythonoracle The Python Oracle. Speech synthesis, with different accents. Cute!
The history of mathematics is a fascinating narrative that charts the development of mathematical concepts, systems, and practices throughout human civilization. It encompasses various periods, cultures, and significant figures who contributed to mathematical thought. Here's an overview of its key milestones: ### Ancient Mathematics (circa 3000 BCE – 500 CE) 1. **Mesopotamia**: The Sumerians developed a base-60 (sexagesimal) number system, which influenced our timekeeping and angles.
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 3. Visual Studio Code extension installation.
Figure 4. Visual Studio Code extension tree navigation.
Figure 5. Web editor. You can also edit articles on the Web editor without installing anything locally.Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.Video 4. OurBigBook Visual Studio Code extension editing and navigation demo. Source. 
- Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact