Xah Lee by Ciro Santilli 40 Updated 2025-07-16
fuseki.net/home/List-of-Patreon-Subs-with-Justification.html describes him well:
Outsider, formerly homeless, extreme person interested in CS and culture. Self-publishes a website with thousands of tutorial / opinion pages. Possibly similar to Sam Sloan - extremely productive, wide interests, obsessive, and pretty disagreeable.
Homepage xahlee.org/ says:
Siphon my knowledge into your brain. Assimilate my sensibilities to your spine.
Nice Second brain vibe.
Figure 1.
Xah Lee with some weird statuettes of himself
. Source. 2019.
Let's see:
Ciro Santilli's energy throughout the day varies as follows:
  • morning: highest
  • 11AM: peak exercise performance
  • after lunch: brain death. Possibly due to Ciro's partial Spanish descent?
  • late afternoon and evening: can do some stuff
Ciro has low tolerance to sleep deprivation which makes him very irritable, and low ability to sleep if there is any light. It must have to do with those damned ganglion cell photoreceptors. On the other hand, Ciro Santilli's wife can sleep without any problems with some morning light! It is definitely genetic. Ciro conjectures that people from very Northern parts of the world must have a gene that allows them to sleep even if there is some light, while more equatorial people don't. Maybe: pubmed.ncbi.nlm.nih.gov/33049062/
Ciro has mild olfactory synesthesia for star anise (八角, bajiao), which is widely used in Chinese cuisine and makes Ciro think uncontrollably of the color blue. Ciro does not have any other known synesthesias. He is also prone to nerd sniping form time to time.
Ciro is a reptilian-like being with cold hands and feet and low blood pressure. For this reason he believes that he will die of cancer or some respiratory problem. If the Chinese government doesn't get him first that is. This also partly explains why Ciro is not a big fan of swimming.
Besides Chinese food, Ciro really likes eating fruits and roasted nuts, maybe partly because he was born in Brazil, and partly because of monkey nature, see his Chinese name. At home he is known as "水果大王" (the big king of the fruits). Ciro is also a sucker for yoghurt (natural without added sugars and full fat, fat-tree yoghurt is terrible, often eaten with fruits). Ciro's "favorite drink" could be tonic water with freshly squeezed lemon. Tied with fresh fruit juices. Chocolate-wise, although not a huge fanatic, a Lindt dark chocolate with whole hazelnut pieces bar will do the job.
Ciro does not like receiving or giving gifts on expected social situations like birthdays or Christmas. Ciro believes that every day is equally precious, and can be a day to give, be it through awesome open source software contributions, or if you find something that your friend will like
Ciro has some respiratory allergies. When he was around 5, he had relatively serious asthma crisis which scared his parents to death. Throughout his life, he appears to be allergic at an intermediate level to: mold or dust mites (or whatever it is that old books/pillows have), cats (itching on touch), hay fever (in May in the UK, likely grass pollen). But even outside of hayfever season, Ciro's nose is constantly either running in the cold, or often partially blocked while sleeping throughout the year. Ciro believes however that this also gives him higher resistance to viral infections, since it has been many many years since he had a cold/flu, and when everyone in the office is going down with it, he's just fine. Ciro wonders if his active immune system will actually kill off cancers early, which he ranks as his most likely causes of death, along with respiratory and gastro-intestinal problems. Ciro has low blood pressure and cannot get fat, so cardio vascular problems seem much less likely.
Ciro is generally democrat due to his high compassion level. He believes that politics is highly genetically determined, and that just like you enter a room full of people and immediately like some and dislike others, the same goes for politics. People just vote for whoever they want to see more of because their way of speaking makes them feel good. There is not rationality involved in it at all.
Ciro self diagnoses a slight graphomania in the early 2020's. This is largely what led him to create OurBigBook.com, and contribute to Stack Overflow. Literature Nobel Prize laureate Naguib Mahfouz also suffers from the condition however, so maybe good can also come out of it:
If the urge to write should ever leave me, I want that day to be my last.
When Ciro was quite young, maybe around 7-10, when he got very angry or sad for some stupid reason (bullying perhaps? Ciro forgot), he would have a psychosomatic manifestation: his spine would become visibly curved sideways (scoliosis). While writing this paragraph, Ciro Googled it, and found e.g. medium.com/@michaelrosen_94192/the-root-cause-of-scoliosis-5c461002b634 that describes:
The Root Cause of Idiopathic Scoliosis
It is proposed that Adolescent Idiopathic Scoliosis (AIS) is a condition created by emotional stress. Evidence is presented that unresolved emotional stress can cause unbalanced tensions in the fascia and growing muscles that gradually deform the spinal column.
so it is a somewhat well known thing! Incredible. Can you imagine the level of the passions that lead to such physical deformations? But of course, it was all for nothing.
Just enough money to raise 3 kids in a rich country without having to work (so he can focus on whatever project he wants) and no more. Then maximize fame.
Fame is slightly convertible into money with generally little liquidity, but is more valuable if money becomes useless in a TEOTWAWKI.
Of course, in the end, one just does whatever seems cool and useful, and the Gods decide what proportion of fame/money/power they will get. Due to Ciro's love of open source software however, a higher fame percentage seems more likely than money.
Searching just for just "Santilli" on Google does not give any Ciro Santilli hits. The name appears to be a minor variation of the much more common "Santini". Since the name is not that common, it is possible to go over all noteworthy hits. Some relevant ones are shown at: interesting members of the Santilli family.
Searching just for just "Ciro" on Google does not give any Ciro Santilli hits, mostly some smaller brands that could be beaten, this is Ciro's main initial fame metric goal. Reaching it would require doing things known much beyond the programming community however, as Ciro has done until of 2019. ciro.com is from an electromechanics consultancy as of 2019, so it's not bad, let them be.
At the next useless gamified level, an honorary OBE and more ambitiously ForMemRS from the Royal Society post nominal letters would be nice.
The ultimate dream however would be to beat Cyrus the Great himself on Google searches ("Ciro" == "Cyrus" in Portuguese), maybe becoming "Cyrus the Greater"? That one will be a bit harder though. Maybe if Falung Gong becomes the dominant religion in 2000 years like Christianism did, catapulting the Judaism benefactor Cyrus into greater fame, then there is some hope for Ciro as well.
This is how Ciro Santilli evaluates himself on the Big Five personality traits:
Ciro Santilli's dreams by Ciro Santilli 40 Updated 2025-07-16
Ciro Santilli's dreams almost all include the following aspect: Ciro is trying to do something mundane, like climbing a hill, walking across town, etc. but doing so it extremely difficult. The hill is too steep, he gets lost, and things which are easy to use in real life are impossibly hard to use in the dream.
So they are a bit like nightmares, but not that bad. Just really annoying and tiresome. Still, Ciro does enjoy o visiting the semi-real places those dreams bring him to, much for the same reasons he enjoys cycling.
Ciro attributes this type of dream to his occupation as a software engineer, because that's basically the feeling you get all day from it: why isn't this working!!! It is so basic!!!
Ciro Santilli has an undiagnozed condition where his upper legs and lower torso often start to itch when he runs, to the point of being extremely annoying and removing all pleasure form the activity.
If some doctor knows why this could be, please tell him!!!
The problem is a bit hard to reproduce however, and Ciro hasn't been able to determine which exact condition triggers it: temperature, nutrition, something else?
Ciro believes that this is not chiefly due to transpiration, but rather to the impact motion that running does on the muscles, as he has felt something similar on his arms some times while cycling in very rough terrain, which made his arms shake in a similar fashion. or for example if he has a water bottle on a tightly tied backpack that rubs his back, then the back itches at that point.
Also, running on a threadmill is not a problem at all. Ciro believes that this is because the threadmill is better amortized, and therefore does not cause the same mechanical stress required to create the itching as running on pavement.
Interestingly, Ciro didn't feel that at all when he played soccer enthusiastically as a child, and he was one of the fastest runners of the group for sure at that time. So he's not sure if it started when he got older, or if it is just because the difference in workloads between soccer and running.
youtu.be/PNgYW5N95z8?t=945 "My back itches" after riding on a bumpy makeshift motorcycle.
Sometimes, these are more than just mechanics, but also have deeper life analogues. The title of Zen and the Art of Motorcycle Maintenance comes to mind. Sometimes they are just mechanics.
With more philosophical metaphors:
  • when your bike breaks, that provides an unique opportunity to learn how to fix it: try to fix your own bike before taking it to the shop
  • if the wind is blowing against you on the way out, it will likely blow behind you on the way back. But remember that the other way around also applies.
  • always take one extra clothing layer than what you think you will need in your back pocket or sport bag, especially when time is changing fast in Sprint and Autumn. The weather on the road outside of town can change very quickly!
  • if you took a turn, and it feels wrong, stop to check the map, and possibly backtrack to safety. When it feels wrong, it usually is a bad idea, e.g. roads where cars are too fast/too many. But if you take a wrong turn and it feels right, then follow it without fear and see what it leads to!
  • don't carry a speedometer on your bike. Analysis can be done afterwards on Strava. The only measurement that matters is "how awesome am I feeling right now?". Live in the moment instead of checking your speedometer every 10 seconds.
  • cycle when you body calls it out of addiction, not out a goal that you've made up that must be reached
With less philosophical metaphors:
  • learn how much water and food you need to take for a trip. Otherwise, you will bonk at some time, when you least expect, it happens very suddenly.
    And then you better hope to God that you can find a food shop nearby. Luckily this was the case for Ciro's first and only bonk so far.
    And besides bonking all out, being tired and hungry makes you make stupid decision, especially where traffic is involved!
    Food is safety. Light is safety. Time is safety. Calm is safety. Chocolate bars and candy cannot count as lunch food, only delay lunch. A sandwich with ham cheese and salad is food. A bag of M&M's with a can of soda can bring you back from the dead.
    When you are not in familiar grounds, take twice as much as you think you might possibly ever need. Hofstadter's law.
    You will also learn that, surprise surprise, carbohydrates that you ate one or two days before a ride stay stored in your liver and muscles, and also greatly affect how quickly you will bonk, thus the concept of carbohydrate loading.
    Video 1.
    How Not To 'Hit The Wall' Or 'Bonk' – GCN's Guide To Fuelling While Cycling by Global Cycling Network (2016)
    Source.
    And surprise surprise: heat can also make you bonk! Who would have thought!
  • correct saddle hight is fundamental, your legs must be almost fully stretched at the bottom position
  • it is impossible to reach the correct tire pressure with (cheap?) hand pumps, their only purpose is to fill up a flat tire so you can get home after a long ride. But a track pump.
  • clean and lube your chain. The speed benefit is instantaneous and mind blowing. It also greatly improves gear shifting.
    This also prevents the chain from rusting, because the lube takes up the place where water would stay, and the muck makes it harder for water to evaporate.
    This is the most common bike maintenance mistake you see on the streets: people with that high pitched overly dry chain noise.
    Video 2.
    How To Get A Perfectly Clean Chain by GCN (2016)
    Source.
  • when a piece on your bike breaks and has no clear name written on it, you can try to identify it Google images
  • the more you watch YouTube maintenance videos without haste, the more you end up learn random new stuff that unexpectedly saves you later
  • if you took a turn, and it feels wrong, stop to check the map, and possibly backtrack to safety. When it feels wrong, it usually is a bad idea, e.g. roads where cars are too fast/too many
  • public place with lots of people are bicycle parking Hell, because due to anonymity and the large number of distractions, it becomes exponentially more likely that someone will fuck you bike somehow, e.g. by dropping it on the ground. Always search a bit for a reasonable place to park, and avoid overcrowded parking spaces at all costs.
  • gear change matters
    • when you get on your bike to start riding, start riding slowly and gradually switch up pedal forces and gears. Things may have shifted in a weird position as it gets kicked around in parking. Ciro managed to bend his derailleur like that!
    • spin to win, AKA learn to user your gears
    • it is not shameful to ride on your lower gears on a hill. You can actually go surprisingly fast with them, and conserve energy for later. Learn when to use each gear ratio.
  • learn to identify your suppliers:
  • always take your lights off the bike into your bag when you park, anywhere, and for any amount of time, even if a quick stop. Drug addicts are everywhere, always ready love to steal and resell them.
  • sometimes you do something stupid like going into a really muddy path, and it is really fun, because you've never been there in your life. But then your bike gets really dirty, and your feet are wet and freezing, and you promise yourself you will never do something that stupid again. But then you do it again in a different location, because it was too much fun. Once more unto the breach just comes to Ciro's mind every such time. Embrace this.
Some other idealists that are a bit further out but with some similarities:
Ciro Santilli also things of those people as being part of his 108 Stars of Destiny troupe.
Ciro sometimes ponders why is it so hard to find people online that you truly love and admire. Maybe it is for similar reasons why it is also hard in the real world: the great variety of human interest, and the great limitation of our attention spans. But online, where we have access to "everyone", shouldn't it should be easier? Not naturally finding such people is perhaps one of the greatest failings of our education system.
Ciro Santilli never did any illegal drugs, because he:
so don't expect any amazing stories here.
Like LDS believers, Ciro never drinks coffee nor smokes, and only drinks alcohol and tea sparingly, because they are all addictive drugs and bring no net increase of energy and concentration.
Ciro prefers to only enjoy a glass of tea when going out cycling on a cold day (Earl gray, with milk, no sugar), or get a half pint of beer when going out with friends to a pub.
Ciro only got reasonably drunk twice on his life:
  • once when he was quite young, likely pre-10 years old, while visiting an uncle's home, and adults were having a very nice sweet and thick type of alcoholic cocktail, and Ciro drank a bit too much and that made him really really stupid
  • once while studying at University of São Paulo, somehow someone was giving free beers at one of the parties (at which Ciro practiced Cirodance). And since Ciro had always been a cheap-ass, he thought, hey, this is a good chance to try it out. Ciro remembers that this made him a bit euphoric, active, very stupid, and a bit horny (though of course, he got no pussy as usual).
Later in life, around the time of his wedding, there were guests around all the time, and he was drinking beer with them all the time. Then one day, during lunch, Ciro felt a weirdly strong desire to drink one more pint. It was at this point that Ciro realized first-hand what mild, but real, alcohol addiction felt like, and he didn't get that drink, and swore from then on to never drink more than one glass a week, and only with friends at a bar after work. Richard Feynman tells a very similar story on his book Surely You're Joking, Mr. Feynman chapter O Americano, Outra Vez!, see: Section "Richard Feynman's drug use".
"Ciro" is "Cyrus" from Cyrus the Great in both Portuguese and Italian (although with very different pronunciations), thus doubly appropriate given that Ciro Santilli was born in Brazil, and has Italian ancestry.
After he conquered Babylon in 539 BC from the hands Neo-Babylonian Empire, Cyrus the Great did a great service to the Hebrews by allowing war prisoners that were held in Babylon to back to their home Judea, thus terminating the Babylonian captivity. These Jews were imprisoned because they had previously fought a war or revolted against the Neo-Babylonian Empire and lost. As Wikipedia puts it:
According to Isaiah 45:1 of the Hebrew Bible, God anointed Cyrus for this task, even referring to him as a messiah (lit. 'anointed one'); Cyrus is the only non-Jewish figure in the Bible to be revered in this capacity.
He is therefore viewed extremely positively in the good old book. Ciro was quite happy about this name choice by his father, given the human rights connotations of the figure and Ciro Santilli's self perceived compassionate personality.
Particularly fun things related to modern Cyrus are:
Because it belongs to some relatively obscure character of the Bible, the name it has been mostly passed on by writing to every single Christian country, and every single language came up with different way of saying it, because the only place they would possibly hear that name said out loud would be in Church!
As of 2020, the country in which the name is most popular in undoubtedly Italy. In Brazil, it is definitely not common, but also not completely unheard of either, e.g. Ciro Gomes is a notable Brazilian politician.
And Ciro responds to all the versions of the name that he knows of. These include:
  • English:
    • direct English reading of "Ciro" as "See Roll". Not the most cultured, but its what things tend to converge to, especially in highly international environments where it would be impossible to try and learn the origin of everyone's name! So it's fine. Slightly too close to "zero" for comfort.
    • Cyrus, the actual English version of the name. Ciro was so happy when his elderly English neighbour who went to Eton College, upon recognizing what Ciro was, immediately said: "Ah, Cyrus the Great!" He was the cutest, and he had some culture. Many/most English speaking people can't or won't be very sure about the spelling, but the sound of the name has a distinctly exotic feel to it, and the sounds are immediately recognized without sound ambiguity (unlike Ciro vs Zero).
  • French:
    • direct French reading of "Ciro" as "See Rho" with accent on Rho. This sounds exactly like "Sirop", i.e. Syrup in French, which can be good or bad depending on how you look at it.
    • Cyrus, the actual version of the name in French. Similar remarks to those of English apply.
  • Portuguese: "See Ru" with accent on See, and rolling r, and very weak "u". Some people might have some doubt of how to spell it and will ask for confirmation if needed, though many/most will get it right. Not particularly exotic like it is for English speakers.
  • Italian: "Chee Ro" with accent on Chee and rolling r. Widely understood and correctly spelled, more than in any other language. Not exotic at all, could be any random dude from Naples.
  • German: Kyrus. Because Cyrus the Great is known Kyrus II. (Cyrus the Second, his grandfather was also called Cyrus), Ciro once joked to a German friend that he should call him Kyrus III! He liked that.
and glad to add any new ones as they come.
  • Persian (spoken in 2020s Iran): something like Kurush. Likely the closest sound one to the original, though not sure how certain we can be of this.
He is actually quite happy when people use the name in their own language, because that means they understand the origin of the name.
Some Ciro's of interest:
Stack Exchange solves to a good extent the use cases:
points of view. It is a big open question if we can actually substantially improve it.
Major shortcoming are mentioned at idiotic Stack Overflow policies:
This website basically aims to be a learning management system, allowing in particular a teacher to focus his help on students that he is legally obliged to help due to their job. But it will have the following unusual characteristics in current LMS solutions:
  • public first, to allow reuse across universities, rather than paywalled as is the case for most top universities
  • students can create material just like teachers, both are on equal footing. Students/teachers will see an indicator "this is your teacher"/"this is your student for this/past semester", but that is the only difference between their interfaces.
In this section we will gather some more advanced ideas besides the basic features described at how the website works.
It would be really cool to have a PageRank-link algorithm that answers the key questions:
However, Ciro has decided to leave this for phase two action plan, because it is impossible to tune such an algorithm if you have no users or test data.
Perhaps it is also worth looking into ExpertRank, they appear to do some kind of "expert in this area", but with clustering (unlike us, where the clustering would be more explicit).
Other dump of things worth looking into:
LOGCFL is a complexity class that stands for "Logarithmic Space Context-Free Languages." It is a subclass of context-free languages that can be recognized by a deterministic pushdown automaton operating in logarithmic space. More formally, a language is in LOGCFL if it can be decided by a deterministic Turing machine that uses logarithmic space and is able to make use of a stack, like a pushdown automaton.

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