MathWorld by Ciro Santilli 40 Updated 2025-07-16
Written mostly by Eric W. Weisstein.
Ciro once saw a printed version of the CRC "concise" encyclopedia of mathematics. It is about 12 cm thick. Imagine if it wasn't concise!!!
Infinite Napkin is the one-person open source replacement we needed for it! And OurBigBook.com will be the final multi-person replacement.
NLab by Ciro Santilli 40 Updated 2025-07-16
Decent encyclopedia of mathematics. Not much motivation, mostly statements though.
Unlike Wikipedia, they have a more sane forum commenting system, e.g. a page/forum pair:
Blockchain wiki by Ciro Santilli 40 Updated 2025-07-16
This section is about wikis that are hosted on a blockchain of some sort.
Golden (wiki) by Ciro Santilli 40 Updated 2025-07-16
April 2024: merged with some fraud protection thing, is it sill a Wiki? Unclear, seem sto have lost that aspect: twitter.com/judegomila/status/1783028847983956430
techcrunch.com/2019/04/30/golden-launch/
To state the obvious: Wikipedia is an incredibly useful website, but Gomila pointed out that notable companies and technologies like SV Angel, Benchling, Lisk and Urbit don’t currently have entries. Part of the problem is what he called Wikipedia’s “arbitrary notability threshold,” where pages are deleted for not being notable enough. (This is also what happened years ago to the Wikipedia page about yours truly — which I swear I didn’t write myself.)
Exactly! Deletionism on Wikipedia is so sad, and especially for companies. In particular e.g. Ciro Santilli tried to create a page for PsiQuantum, and it got reverted... and now golden has one of the largest Google hits for it: golden.com/wiki/PsiQuantum-PBDGXRA
TODO how do they do moderation?
As of April 2024
Login is currently disabled.
Asked at: twitter.com/cirosantilli/status/1777250258235302233 Their last tweets were from August 2023, so maybe they just silently shutdown? Their name is too generic and hard to search for efficiently...
They do have knowledge graph built-in which is cool.
Nature Scitable by Ciro Santilli 40 Updated 2025-07-16
As of 2022 visible at: www.nature.com/scitable
Apparently they had a separate URL as just scitable.com, so they were somewhat serious about it before shutting it down.
As of 2022 marked:
This page has been archived and is no longer updated
RIP.
www.nature.com/scitable/blog/student-voices/ has last entry 2015, so presumably that's the shutdown year.
Self description:
Using our platform, you can customize your own eBooks for your students. Create an online classroom. Contribute and share content and connect with networks of colleagues.
so quite related to OurBigBook.com.
Wikipedia by Ciro Santilli 40 Updated 2025-07-16
The most important page of Wikipedia is undoubtedly: en.wikipedia.org/wiki/Wikipedia:Reliable_sources/Perennial_sources which lists the accepted and non accepted sources. Basically, the decision of what is true in this world.
Wikipedia is incredibly picky about copyright. E.g.: en.wikipedia.org/wiki/Wikipedia:Deletion_of_all_fair_use_images_of_living_people because "such portrait could be created". Yes, with a time machine, no problem! This does more harm than good... excessive!
Citing in Wikipedia is painful. Partly because of they have a billion different templates that you have to navigate. They should really have a system where you can easily reuse existing sources across articles! Section "How to use a single source multiple times in a Wikipedia article?"
Video 1.
What Happened To Wikipedia's Founders?
Source.
Some examples by Ciro Santilli follow.
Of the tutorial-subjectivity type:
Notability constraints, which are are way too strict:
There are even a Wikis that were created to remove notability constraints: Wiki without notability requirements.
For these reasons reason why Ciro basically only contributes images to Wikipedia: because they are either all in or all out, and you can determine which one of them it is. And this allows images to be more attributable, so people can actually see that it was Ciro that created a given amazing image, thus overcoming Wikipedia's lack of reputation system a little bit as well.
Wikipedia is perfect for things like biographies, geography, or history, which have a much more defined and subjective expository order. But when it comes to "tutorials of how to actually do stuff", which is what mathematics and physics are basically about, Wikipedia has a very hard time to go beyond dry definitions which are only useful for people who already half know the stuff. But to learn from zero, newbies need tutorials with intuition and examples.
Bibliography:
Wikipedia lore by Ciro Santilli 40 Updated 2025-07-16
Video 1.
What Mental Breakdown Of a Wikipedia Moderator looks like by Vince Vintage
. Source.
dumps.wikimedia.org/enwiki/latest/enwiki-latest-category.sql.gz contains a list of categories. It only contains the categories and some counts, but it doesn't contain the subcategories and pages under each category, so it is a bit pointless.
The SQL first defines the table:
CREATE TABLE `category` (
  `cat_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `cat_title` varbinary(255) NOT NULL DEFAULT '',
  `cat_pages` int(11) NOT NULL DEFAULT 0,
  `cat_subcats` int(11) NOT NULL DEFAULT 0,
  `cat_files` int(11) NOT NULL DEFAULT 0,
  PRIMARY KEY (`cat_id`),
  UNIQUE KEY `cat_title` (`cat_title`),
  KEY `cat_pages` (`cat_pages`)
) ENGINE=InnoDB AUTO_INCREMENT=249228235 DEFAULT CHARSET=binary ROW_FORMAT=COMPRESSED;
followed by a few humongous inserts:
INSERT INTO `category` VALUES (2,'Unprintworthy_redirects',1597224,20,0),(3,'Computer_storage_devices',88,11,0)
which we can see at: en.wikipedia.org/wiki/Category:Computer_storage_devices
Se see that en.wikipedia.org/wiki/Category:Computer_storage_devices_by_company
so it contains only categories.
We can check this with:
sed -s 's/),/\n/g' enwiki-latest-category.sql | grep Computer_storage_devices
and it shows:
(3,'Computer_storage_devices',88,11,0
(521773,'Computer_storage_devices_by_company',6,6,0
There doesn't seem to be any interlink between the categories, only page and subcategory counts therefore.

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!
We have two killer features:
  1. 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-calculus
    Articles 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/derivative
  2. 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.
    Figure 2.
    You can publish local OurBigBook lightweight markup files to either https://OurBigBook.com or as a static website
    .
    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.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
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