| Deno | |
|---|---|
 Logo used since 2024 | |
| Original author | Ryan Dahl |
| Developers | Deno Land Inc[1] and contributors |
| Initial release | May 13, 2018; 7 years ago (2018-05-13)[2] |
| Stable release | |
| Written in | Rust,TypeScript,JavaScript |
| Operating system | Linux,macOS,Microsoft Windows |
| Type | Runtime environment |
| License | MIT License[4] |
| Website | deno |
| Repository | github |
Deno (/diːnoʊ/[5]) is aruntime forJavaScript,TypeScript, andWebAssembly that is based on theV8 JavaScript engine and theRust programming language. Deno was co-created byRyan Dahl, the creator ofNode.js[6], and Bert Belder.[7]
Deno explicitly takes on the role of both runtime andpackage manager within a singleexecutable, rather than requiring a separatepackage-management program.[5][8]
Deno was announced at JSConf EU 2018 byRyan Dahl in his talk "10 Things I Regret About Node.js".[9] In his talk, Dahl mentioned his regrets about the initial design decisions with Node.js, focusing on his choices of not usingpromises inAPI design, usage of the legacy build systemGYP, node_modules and package.json, leaving outfile extensions, magical module resolution with index.js and breaking the sandboxed environment of V8.[10] He eventually presented the prototype of Deno, aiming to achieve system call bindings through message passing with serialization tools such asProtocol Buffers, and to provide command line flags foraccess control.
Deno was initially written inGo and usedProtocol Buffers for serialization between privileged (Go, with system call access) and unprivileged (V8) sides.[11] However, Go was soon replaced withRust due to concerns of double runtime andgarbage collection pressure.[12]Tokio was introduced in place oflibuv as the asynchronous event-driven platform,[13] andFlatBuffers was adopted for faster, "zero-copy" serialization and deserialization[14] but later in August 2019, FlatBuffers was removed[15] after publishing benchmarks that measured a significant overhead of serialization in April 2019.[16]
A standard library, modeled after Go's standard library, was created in November 2018 to provide extensive tools and utilities, partially solving Node.js'dependency tree explosion problem.[17]
The official Deno 1.0 was released on May 13, 2020.[18]
Deno Deploy, inspired byCloudflare Workers,[19] was released on June 23, 2021.[20] Announced May 4, 2022 Beta 4 improved the dashboard and added billing functionality.[21]
Deno Fresh 1.0 was announced June 28, 2022.[22] It features a new full stack web framework for Deno that by default sends zero JavaScript to the client. The framework has no build step which allows for an order of magnitude improvements in deployment times. Version 1.1 was released September 8, 2022.[23]
Deno SaaSKit beta was announced April 4, 2023.[24] It is an open-source, modern SaaS template built with Fresh and Deno.
Deno 2 was released October 9, 2024.[25] It primarily brings Node.js compatibility improvements and removes deprecated features.
Deno aims to be a productive and securescripting environment for the modern programmer.[5] Similar to Node.js, Deno emphasizesevent-driven architecture, providing a set ofnon-blocking core I/O utilities, along with their blocking versions. Deno could be used to createweb servers, perform scientific computations, etc. Deno isopen source software under theMIT License.[26]
Deno and Node.js are both runtimes built on theV8 JavaScript engine developed by the Chromium Project, the engine used forChromium andGoogle Chrome web browsers. They both have internalevent loops and providecommand-line interfaces for running scripts and a wide range of system utilities.
Deno mainly deviates from Node.js in the following aspects:[5]
npm: andnode: to import NPM or polyfill Node.JS modules. Node.js supports both URLs[29] and modules.On March 29, 2021, Deno Land Inc was announced, with backing in millions of dollars fromShasta Ventures,Mozilla Corporation and a few others. It was established to further the development of Deno and provide a commercial offering to users.[1]
A year on, Deno announced a further $21 million in Series A funding led bySequoia Capital.[33]