Graydon Hoare, Rust and the Broken Elevator – La Biblia de la IA

Biographies · Programming languages and AI infrastructure

Graydon Hoare lived on the twenty-first floor. In 2006, when the elevator in his Vancouver apartment building failed again, the distance between a software problem and his own front door was a long climb up the stairs. Nearly two decades later, invited to tell the story of Rust, he remembered the annoyance. He also remembered how little the first version of his language could do.

Twenty-one floors

Clive Thompson opens his 2023 profile with the climb. Hoare was twenty-nine and worked for Mozilla. Thompson describes a software crash and pictures him opening his laptop to begin designing a language. In his own account in 2025, Hoare confirmed the broken elevator and the year. The precise fault in the controller remains unknown. The experience gave a familiar frustration a particularly physical form for someone who made software for a living. Thompson’s report · Hoare’s recollection.

Hoare is a Canadian engineer who has spent much of his working life making tools for other people. He has worked at Red Hat, Mozilla, Apple and Stellar. Asked what he actually did all day, he described dividing his time between a text editor and conversations with colleagues. His work included compilers, which translate a program into a form a computer can run, and tools that help people find out why a program is slow or behaves unexpectedly. At home he liked to walk along the ocean and read history. The history of his own trade was a particular pleasure. His 2019 interview · Hoare on his influences.

A language assembled from older ideas

At work he regularly wrestled with C++. In his spare time he could choose languages whose rules made some mistakes easier to catch. He wanted some of that freedom at work. Languages such as ML, Ada and Cyclone had already explored ideas he could use. Even his account of the name has the informality of a personal project. Asked where “Rust” came from, he recalled, with some hesitation, the rust fungi and the elaborate life cycles that had caught his imagination. Interview on the early design · Hoare’s exchange about the name.

One problem becomes clear if you imagine a program holding a line of text in memory. One part finishes with the text and releases the space. Another still holds a reference and tries to read it. The computer may already have reused that space for something else. In safe Rust the compiler checks how long a reference may live. It rejects a program when it cannot establish that the text will still exist when the reference is used. The programmer gets the question while there is still time to revise the code. Other errors remain possible. A program can handle its memory correctly and still send an elevator to the wrong floor. The Rust book on borrowing.

The prototype finds a team

Hoare’s surviving archive places the personal project between 2006 and 2009. Late in 2009 Mozilla began funding development. At its July 2010 summit he presented a language he had spent roughly four and a half years building. The early prototype could run small demonstrations. Mozilla subsequently backed Servo, an experimental browser engine. A browser must lay out pages and respond to input while several things happen at once. It gave the developers a substantial piece of software against which to test their ideas. Hoare’s archive · His summit slides · Hoare on Servo.

Some of those ideas changed hands and changed shape. Dave Herman, who had worked with Hoare on an earlier language project, contributed code and helped guide discussions at Mozilla. Early Rust allowed an automatic memory collector in some circumstances. The team eventually settled on ownership and borrowing as the language’s central rules for managing memory. Hoare stepped away from Rust in 2013. At Apple he later worked on Swift, where the main design was already in place. He describes a quieter role improving its compiler and tracking down faults. A colleague’s account of Herman · Hoare on Rust and Swift.

On 15 May 2015 the Rust Core Team released version 1.0. Stability meant that people could build software against the language and expect it to keep working across later stable releases. When the Rust Foundation was formed in 2021 it took on work such as supporting infrastructure and holding trademarks. Technical decisions continued within the Rust Project. In 2023 its teams established a Leadership Council for matters that cross team boundaries. The 1.0 announcement · Mozilla on the Foundation · The Project on its governance.

Before a model reads a sentence

Much of Rust’s subsequent life has been out of sight. Google used it in Android’s Keystore2, which helps protect cryptographic keys. Microsoft used it for a security component of Azure IoT Edge. Amazon Web Services developed Firecracker, which runs workloads in small, isolated virtual machines. In each case the component has a specific job that users seldom have occasion to name. Android · Microsoft · Firecracker.

Something similar happens when a reader sends a sentence to a language model. The text first has to be split into units called tokens and converted into numbers. Depending on the vocabulary learned by the tokenizer, a single word may become several pieces. Hugging Face’s Tokenizers library does this work in Rust, even when the person using it is writing in Python. Its Candle framework uses Rust for a different job, including running trained models. Both are the work of later teams. They show how a decision made by the builders of a tool can reach people who have never heard its author’s name. Tokenizers · From text to numbers · Candle.

In his tenth-anniversary essay Hoare gave as much attention to the people who test, teach, translate and maintain Rust as to the first compiler. There is a fitting symmetry in that choice. The broken elevator made the machinery of his building impossible to ignore. A working one would have let him get home thinking about something else. Hoare’s anniversary essay.

A chronology

2006 · VancouverBegins the personal project that becomes Rust.
2009–2010 · MozillaReceives institutional support in late 2009 and presents Rust at the July 2010 summit.
2012–2013Servo becomes a testing ground for Rust. Hoare steps away from the language project in 2013.
2015The Rust Core Team releases version 1.0 on 15 May.
2021–2023The Foundation is formed in 2021. The Project establishes its Leadership Council in 2023.
2025Hoare marks a decade of stable Rust with an essay on the people who built and sustained it.