Wikipedia will be 25 years old in January. Jimmy Wales’s daughter will be 25 and three weeks. It’s not a coincidence: on Boxing Day 2000 Wales’s then wife, Christine, gave birth to a baby girl, but it quickly became clear that something wasn’t right. She had breathed in contaminated amniotic fluid, resulting in a life-threatening condition called meconium aspiration syndrome. An experimental treatment was available at the hospital near where they lived in San Diego. Did they want to try it?

At the time, Wales was a former trader and internet entrepreneur in his mid-30s. He had co-founded a “guy-oriented search engine” called Bomis, but his real passion was encyclopedias. The money from Bomis had allowed him to found Nupedia, a free online encyclopedia written by experts – but it was proving slow to get off the ground. The laborious process of peer review meant that it only managed to generate 21 articles in its first year (among them “Donegal fiddle tradition” and “polymerase chain reaction”).

Suddenly, Wales needed information, and fast. But as he searched for “meconium” on the wider web, desperate to make a better-informed decision about his daughter’s health, all he found was a mixture of first-hand accounts from strangers he had no way of evaluating and highly technical scientific papers he couldn’t understand. “It was like sifting through the debris of a bombed-out library,” he remembers. Ultimately, he and his then wife decided to trust the doctors and go with the new treatment. Their baby, Kira, pulled through. But that terrifying scramble made up his mind: Nupedia was never going to work – it was time for a different approach.

We know the rest of the story: his new project, Wikipedia, founded on the principle that anyone could edit it, grew rapidly. By 2002, there were about 25,000 entries in the English version; by 2006, there were 1m. There are now more than 7m (the digital version of Encyclopedia Britannica has 100,000). Alongside this are 18 foreign-language versions of Wikipedia that have more than 1m articles each, ranging from Arabic to Vietnamese. It has become part of the plumbing of the internet – perhaps even more essential: Diane von Fürstenberg once told Wales that “we all use Wikipedia more often than we pee”.

In an online landscape characterised by doom and division, it stands out: a huge, collective endeavour based on voluntarism and cooperation, with an underlying vision that’s unapologetically utopian – to build “a world where every single person on the planet is given free access to the sum of all human knowledge”. It has weathered teething troubles (such as a “joke” edit that suggested a loyal aide to Robert F Kennedy was in fact involved in his and his brother’s assassinations) to become a place in which civility and neutrality are the guiding stars, and levels of accuracy match those of academic textbooks.

Wales’s new book, The Seven Rules of Trust, is an attempt to distil the secrets of its success. They include things such as having a strong, clear, positive purpose (the slogan “Wikipedia is an encyclopedia” is a surprisingly powerful reminder that keeps editors honest); assuming good faith and being courteous; refraining from taking sides and being radically transparent. It’s a no-nonsense “lessons learned” book that might otherwise find itself occupying shelf space next to Steven Bartlett’s Diary of a CEO (subtitle: The 33 Laws of Business and Life) – but Wikipedia’s ubiquity, and the way it has dramatically bucked the trend of online toxicity – make it potentially far more significant.