Rust is a general-purpose programming language. It is noted for its emphasis on performance, type safety, concurrency, and memory safety.

Rust supports multiple programming paradigms. It was influenced by ideas from functional programming, including immutability, higher-order functions, algebraic data types, and pattern matching. It also supports object-oriented programming via structs, enums, traits, and methods. Rust is noted for enforcing memory safety (i.e., that all references point to valid memory) without a conventional garbage collector; instead, memory safety errors and data races are prevented by the "borrow checker", which tracks the object lifetime of references at compile time.

Software developer Graydon Hoare created Rust in 2006 while working at Mozilla, which officially sponsored the project in 2009. The first stable release, Rust 1.0, was published in May 2015. Following a layoff of Mozilla employees in August 2020, four other companies joined Mozilla in sponsoring Rust through the creation of the Rust Foundation in February 2021.

Rust has been adopted by many software projects, especially web services and system software, and is the first language other than C and assembly to be supported in the development of the Linux kernel. It has been studied academically and has a growing community of developers.

Rust began as a personal project by Mozilla employee Graydon Hoare in 2006, who started the project due to his frustration with a broken elevator in his apartment building. Hoare named Rust after the group of fungi that is "over-engineered for survival". During the time period between 2006 and 2009, Rust was not publicized to others at Mozilla and was written in Hoare's free time; Hoare began speaking about the language around 2009 after a small group at Mozilla became interested in the project. Hoare cited languages from the 1970s, 1980s, and 1990s as influences — including CLU, BETA, Mesa, NIL, Erlang, Newsqueak, Napier, Hermes, Sather, Alef, and Limbo. He described the language as "technology from the past come to save the future from itself." Early Rust developer Manish Goregaokar similarly described Rust as being based on "mostly decades-old research."

During the early years, the Rust compiler was written in about 38,000 lines of OCaml. Features of early Rust that were later removed include explicit object-oriented programming via an obj keyword, and a typestates system that would allow variables of a type to be tracked along with state changes (such as going from uninitialized to initialized).

Mozilla officially sponsored the Rust project in 2009. Brendan Eich and other executives, intrigued by the possibility of using Rust for a safe web browser engine, placed engineers on the project including Patrick Walton, Niko Matsakis, Felix Klock, and Manish Goregaokar. A conference room taken by the project developers was dubbed "the nerd cave," with a sign placed outside the door.

During this time period, work had shifted from the initial OCaml compiler to a self-hosting compiler, i.e., written in Rust, based on LLVM. The Rust ownership system was also in place by 2010.