Deno (/diːnoʊ/[5]) is a runtime for JavaScript, TypeScript, and WebAssembly that is based on the V8 JavaScript engine and the Rust programming language. Deno was co-created by Ryan Dahl, who also created Node.js.[6]
 Logo used since 2024 | |
| Original author(s) | Ryan Dahl |
|---|---|
| Developer(s) | Deno Land Inc[1] and contributors |
| Initial release | May 13, 2018[2] |
| Stable release | 2.1.1[3] 
/ 21 November 2024 |
| Repository | github |
| Written in | TypeScript, JavaScript, Rust, C++ (V8 bindings) |
| Operating system | Linux, macOS, Microsoft Windows |
| Type | Runtime environment |
| License | MIT License[4] |
| Website | deno |
Deno explicitly takes on the role of both runtime and package manager within a single executable, rather than requiring a separate package-management program.[5][7]
History
editDeno was announced at JSConf EU 2018 by Ryan Dahl in his talk "10 Things I Regret About Node.js".[8] In his talk, Dahl mentioned his regrets about the initial design decisions with Node.js, focusing on his choices of not using promises in API design, usage of the legacy build system GYP, node_modules and package.json, leaving out file extensions, magical module resolution with index.js and breaking the sandboxed environment of V8.[9] He eventually presented the prototype of Deno, aiming to achieve system call bindings through message passing with serialization tools such as Protocol Buffers, and to provide command line flags for access control.
Deno was initially written in Go and used Protocol Buffers for serialization between privileged (Go, with system call access) and unprivileged (V8) sides.[10] However, Go was soon replaced with Rust due to concerns of double runtime and garbage collection pressure.[11] Tokio was introduced in place of libuv as the asynchronous event-driven platform,[12] and FlatBuffers was adopted for faster, "zero-copy" serialization and deserialization[13] but later in August 2019, FlatBuffers was removed[14] after publishing benchmarks that measured a significant overhead of serialization in April 2019.[15]
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.[16]
The official Deno 1.0 was released on May 13, 2020.[17]
Deno Deploy, inspired by Cloudflare Workers,[18] was released on June 23, 2021.[19] Announced May 4, 2022 Beta 4 improved the dashboard and added billing functionality.[20]
Deno Fresh 1.0 was announced June 28, 2022.[21] 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.[22]
Deno SaaSKit beta was announced April 4, 2023.[23] It is an open-source, modern SaaS template built with Fresh and Deno.
Deno 2 was released October 9, 2024.[24] It primarily brings Node.js compatibility improvements and removes deprecated features.
Overview
editDeno aims to be a productive and secure scripting environment for the modern programmer.[5] Similar to Node.js, Deno emphasizes event-driven architecture, providing a set of non-blocking core I/O utilities, along with their blocking versions. Deno could be used to create web servers, perform scientific computations, etc. Deno is open source software under the MIT License.[25]
Comparison with Node.js
editDeno and Node.js are both runtimes built on the V8 JavaScript engine developed by the Chromium Project, the engine used for Chromium and Google Chrome web browsers. They both have internal event loops and provide command-line interfaces for running scripts and a wide range of system utilities.
Deno mainly deviates from Node.js in the following aspects:[5]
- Supports only ES Modules like browsers where Node.js supports both ES Modules and CommonJS. CommonJS support in Deno is possible by using a compatibility layer.[26][27]
- Supports URLs for loading local or remote dependencies, similar to browsers, and uses module specifiers like
npm:andnode:to import NPM or polyfill Node.JS modules. Node.js supports both URLs[28] and modules. - Does not require a package manager for resource fetching, thus no need for a registry like npm.[29]
- Supports TypeScript out of the box,[30] using a snapshotted TypeScript compiler or the swc compiler[31] with caching mechanisms.
- Aims for better compatibility with browsers with a wide range of Web APIs.
- Restricts file system and network access by default in order to run sandboxed code.
- Supports a single API to utilize promises, ES6 and TypeScript features whereas Node.js supports both promise and callback APIs.
- Minimizes core API size, while providing a large standard library with no external dependencies.
- Uses message passing channels for invoking privileged system APIs and using bindings.
Funding
editOn March 29, 2021, Deno Land Inc was announced, with backing in millions of dollars from Shasta 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 by Sequoia Capital.[32]
Release history
editThe tables below were created using the official Releases page.[33]
Deno
edit| Version | Latest patch release | Release date | Date of last patch release | Description |
|---|---|---|---|---|
| 0.1.0 | 0.1.12 | 2018-08-23 | 2018-11-12 | Rust rewrite and V8 snapshot |
| 0.2.0 | 0.2.11 | 2018-11-27 | 2019-02-08 | Mildly usable |
| 0.3.0 | 0.3.10 | 2019-02-18 | 2019-04-25 | Instead of importing a "deno" module, there is now a global variable called "Deno" |
| 1.0.0 | 1.0.5 | 2020-05-13 | 2020-06-03 | Initial production release with CLI, first-class TypeScript Support, Rust APIs and improvements in HTTP server performance |
| 1.1.0 | 1.1.3 | 2020-06-12 | 2020-07-03 | Various additions and fixes to the CLI, Rust 1.44.0 |
| 1.2.0 | 1.2.3 | 2020-07-13 | 2020-08-08 | Various additions and fixes to the CLI |
| 1.3.0 | 1.3.3 | 2020-08-13 | 2020-09-04 | Various additions and fixes to the CLI, various improvements to the Deno language, TypeScript 3.9.7 |
| 1.4.0 | 1.4.6 | 2020-09-13 | 2020-10-10 | New web standard WebSocket API, automatic restarts on file change, integrated test coverage |
| 1.5.0 | 1.5.4 | 2020-10-27 | 2020-11-23 | Faster tree-shaking and bundling, refactored REPL |
| 1.6.0 | 1.6.3 | 2020-12-08 | 2020-12-30 | Compile standalone binaries via "deno compile", support TypeScript 4.1, experimental support for Mac ARM64 |
| 1.7.0 | 1.7.5 | 2021-02-05 | 2021-02-19 | Cross compilation and 60% smaller binaries for deno compile, a DNS resolver API, support for data URLs in import statements and web workers |
| 1.8.0 | 1.8.3 | 2021-03-02 | 2021-04-02 | Experimental support for WebGPU API, built-in internationalization APIs enabled, support for fetching private modules, revamped coverage tooling, support for TypeScript 4.2 |
| 1.9.0 | 1.9.2 | 2021-04-13 | 2021-04-23 | Native HTTP/2 web server, Faster calls into Rust with serde_v8, Blob URL support & improvements to fetch api, Import completions in the LSP, Interactive permission prompt |
| 1.10.0 | 1.10.2 | 2021-05-11 | 2021-05-17 | Improvements to the built in test runner, structuredClone() support in Web Workers, Web Storage API, support for remote import maps
|
| 1.11.0 | 1.11.3 | 2021-06-08 | 2021-06-29 | Official docker images, more web crypto APIs added, BroadcastChannel, abortable fetch, deno lint stabilized |
| 1.12.0 | 1.12.2 | 2021-07-13 | 2021-07-26 | Support for generateKey, sign and verify web crypto APIs, native WebSocket server support, TypeScript support in REPL, support for MessagePort and MessageChannel
|
| 1.13.0 | 1.13.2 | 2021-08-10 | 2021-08-23 | Native HTTP web server stabilization, support for self.structuredClone(), AbortSignal support, support for CODEN avigator.hardwareConcurrency, javascript API, experimental WebSocketStream API, FFI replaces native plugin system
|
| 1.14.0 | 1.14.3 | 2021-09-14 | 2021-10-04 | URLPattern, file locking APIs, mutual TLS support in fetch, TypeScript 4.4, URL parsing and std/http performance improvements
|
| 1.15.0 | 1.15.3 | 2021-10-12 | 2021-10-25 | New crypto APIs, deno uninstall subcommand, nested testing API, FFI improvements, new—compat flag for improved Node compatibility |
| 1.16.0 | 1.16.4 | 2021-11-09 | 2021-12-03 | Fetch support for file URLs, new unstable signal listener API, support for specifying a reason when aborting an AbortSignal, improvements to Web Streams API, findLast and findLastIndex array methods, Deno to npm package build tool
|
| 1.17.0 | 1.17.3 | 2021-12-16 | 2022-01-12 | Import assertions and JSON modules, improvements to the Web Cryptography API, unref timers, unstable support for negotiating ALPN, TypeScript 4.5 |
| 1.18.0 | 1.18.0 | 2022-01-20 | 2022-01-20 | Configuration auto-discovery, completion of Web Cryptography API, stabilization of test steps API, FFI improvements, LSP improvements |
| 1.19.0 | 1.19.3 | 2022-02-17 | 2022-03-10 | New Deno vendor dependency, default permission prompt, new web streams for files, network sockets and stdio, CompressionStream and DecompressionStream supported, better errors for ops and resource sanitizers, improved console log |
| 1.20.1 | 1.20.6 | 2022-04-14 | 2022-03-16 | Faster calls into Rust, auto-compression for HTTP response bodies, new subcommands (deno bench, deno task), security improvements, stricter defaults in programmatic permission, TypeScript 4.6, V8 10.0 |
| 1.21.0 | 1.21.3 | 2022-04-20 | 2022-05-12 | Various improvements to the Deno language, VSCode extension, and REPL. Improvements in Deno Test |
| 1.22.0 | 1.22.3 | 2022-05-18 | 2022-06-09 | Updated default type checking behavior, various improvements to the Deno language, updates to the test runner |
| 1.23.0 | 1.23.4 | 2022-06-15 | 2022-07-12 | No type-checking by default, various improvements to the Deno language, force a new line in REPL, TypeScript 4.7 |
| 1.24.0 | 1.24.3 | 2022-07-20 | 2022-08-11 | Type checking and emitting performance improvements, various improvements to the Deno language, Deno Test improvements, Updates to the new subprocess API, LSP improvements, addition of semver module |
| 1.25.0 | 1.25.4 | 2022-08-24 | 2022-09-22 | deno init subcommand, experimental npm support, new HTTP server API, improvements to startup time, FFI API improvements |
| 1.26.0 | 1.26.2 | 2022-09-29 | 2022-10-17 | Cache Web API, WebCrypto Secure Curves, --allow-sys permission flag, improvements to npm and Node.JS support, improvements to Deno.serve() API, improved module download UI, developer experience improvement, TypeScript 4.8
|
| 1.27.0 | 1.27.2 | 2022-10-27 | 2022-11-08 | Major IDE improvements, improvements to npm compatibility, navigator.language Web API, Improvements to deno task, Upgrade checker, Changes to Deno APIs, Updates to deno lint, V8 10.8, Node.js compatibility improvements, Changes to standard library APIs |
| 1.28.0 | 1.28.3 | 2022-11-13 | 2022-12-01 | Various fixes and feature stabilisations, NPM package importer, auto discovery of the lock file, V8 10.9 |
| 1.29.0 | 1.29.4 | 2022-12-14 | 2023-01-16 | npm compatibility improvements, REPL changes, quality of life improvements, Deno API changes, TypeScript 4.9, standard library updates |
| 1.30.0 | 1.30.3 | 2023-01-26 | 2023-02-07 | Support for built-in Node.js modules (import "node:fs"), deno.json becomes an import map, deno fmt supports configuring semicolons
|
| 1.31.0 | 1.31.1 | 2023-02-24 | 2023-02-25 | Support for package.json, Stabilization of Node-API, Node compatibility layer for NodeJS moved to the Deno runtime itself, Stabilizations in Deno API, Change to pointer type in FFI API |
| 1.32.0 | 1.32.5 | 2023-03-23 | 2023-04-18 | Enhanced Node.js compatibility, deno compile support for web workers and dynamic import, changes to Deno APIs, changes to Web APIs, changes to the standard library, TypeScript 5.0, V8 11.2 |
| 1.33.0 | 1.33.4 | 2023-04-28 | 2023-05-18 | Built in Key-value database, flatter configuration, no permission check for dynamic imports, further enhanced Node.js/npm compatibility, performance improvements, CLI improvements, changes to Deno APIs, V8 11.4 |
| 1.34.0 | 1.34.3 | 2023-05-23 | 2023-6-15 | Deno compile support for npm packages, glob support in Deno.json and CLI flags, support for IP addresses in TLS certificates, configuration file improvements, API Changes, Node.js compatibility improvements, TypeScript 5.0.4, V8 11.5 |
| 1.35.0 | 1.35.3 | 2023-07-05 | 2023-07-26 | New stable web server API, Node.js compatibility improvements, Deno API changes, Web API changes, LSP improvements, updates to standard library, TypeScript 5.1.6, V8 11.6 |
| 1.36.0 | 1.36.2 | 2023-08-03 | 2023-08-21 | More flexible security and expanded testing APIs |
| 1.37.0 | 1.37.2 | 2023-09-19 | 2023-10-12 | Jupyter support, TypeScript 5.2, bug fixes |
| 1.38.0 | 1.38.5 | 2023-11-01 | 2023-12-05 | Deno.Server renamed to Deno.HttpServer, Jupyter support and fixes, Websocket features
|
| 1.39.0 | 1.39.4 | 2023-12-13 | 2024-01-13 | Re-addition of WebGPU support |
| 1.40.0 | 1.40.5 | 2024-01-25 | 2024-02-15 | Temporal API, additional import.meta support, stage 3 decorator support, Deno 2 preparatory deprecations, better import maps, WebGPU windowing, and updates to unstable flags
|
| 1.41.0 | 1.41.3 | 2024-02-22 | 2024-03-14 | Smaller compiled binaries, official Linux ARM64 builds |
| 1.42.0 | 1.42.3 | 2024-02-22 | 2024-03-14 | JSR support |
| 1.43.0 | 1.43.6 | 2024-05-01 | 2024-05-21 | Sped up language server in monorepos, new deno serve, URL.parse() API, Deno 2 feature flag, V8 12.4
|
| 1.44.0 | 1.44.4 | 2024-05-30 | 2024-06-19 | Initial Next.js support, private npm registries, gRPC |
| 1.45.0 | 1.45.5 | 2024-07-10 | 2024-07-31 | Monorepo support with workspaces, deno install updates, command to initialize JSR project, deno vendor deprecation, stabilization of the Standard Library ongoing, V8 12.7 and TypeScript 5.5.2 |
| 1.46.0 | 1.46.3 | 2024-08-22 | 2024-09-04 | CLI simplifications, deno serve multithreading, expanded formatting support, import assertion deprecation, code signing, Playwright support, stable HMR, Standard Library stabilized, CLI additions, V8 12.9 |
| 2.0.0 | 2.0.3 | 2024-10-09 | 2024-10-25 | Node.js compatibility improvements, announced LTS release channel, performance improvements |
Legend: Old version Latest version Future release | ||||
Deno Fresh
editVersion numbers are based on releases from Github.[34]
| Version | Latest patch release | Release date | Date of last patch release | Description |
|---|---|---|---|---|
| 1.0.0 | 1.0.0 | 2022-06-28 | 2022-06-28 | Initial release |
| 1.1.0 | 1.1.6 | 2022-08-09 | 2023-05-23 | Automatic JSX, new twind plug-in, Preact Signals support, Preact DevTools support, explicit rendering of 404 pages, stacked middleware, experimental Deno.serve support, showcase & "Made with Fresh" badges |
| 1.2.0 | 1.2.0 | 2023-06-15 | 2023-06-15 | More datatypes supported in island props, support for passing JSX to islands and nesting islands, support for importing packages from npm, custom HEAD request handlers, overrides for headers and status from ctx.render, asynchronous plugin rendering, simplified testing |
| 1.3.0 | 1.3.1 | 2023-07-18 | 2023-07-21 | Async Route Components. adding routes and/or middlewares from plugin. 500 error template fallback, error Boundaries, export multiple islands in the same file, Fresh linting rules, support for Deno.serve |
| 1.4.0 | 1.4.3 | 2023-08-16 | 2023-09-06 | Faster page loads with ahead-of-time compilation, custom html, head and body tags, layouts (async layouts and async app wrapper, quicker typing with define functions |
| 1.5.0 | 1.5.4 | 2023-10-10 | 2023-09-06 | Partials and CSR support, active link styling, exposed esbuild targets configuration and metafile.json |
| 1.6.0 | 1.6.8 | 2023-12-01 | 2024-03-22 | Tailwind CSS support, partials improvements, bundling improvements, improved plugin API, improved route matching performance, subpaths support, better typings, error overlay is closable |
| 1.7.0 | 1.7.3 | 2024-08-15 | 2024-10-14 | Add Unix domain sockets support |
Legend: Old version Latest version Future release | ||||
Deno SaasKit
editVersion numbers are bases on release numbers from the Github repository.[35]
| Version | Latest patch release | Release date | Date of last patch release | Description |
|---|---|---|---|---|
| beta | beta | 2023-04-04 | 2022-04-04 | Initial release |
| 0.1.0 | 2023-04-19 | |||
| 0.2.0 | 2023-05-08 | |||
| 0.3.0 | 2023-06-06 | |||
| 0.4.0 | 2023-06-20 | Deno KV OAuth | ||
| 0.5.0 | 2023-06-27 | |||
| 0.6.0 | 0.6.1 | 2023-08-06 | 2023-09-12 | |
| 0.7.0 | 2023-12-19 | |||
Legend: Old version Latest version Future release | ||||
Examples
editThis article may require cleanup to meet Wikipedia's quality standards. The specific problem is: Reads like a software tutorial. Some code examples may be useful to illustrate aspects of the framework, but they should be selected for the purpose of providing context to an encyclopedia article on the software. (July 2023) |
A basic Hello, World! program in Deno:
console.log("Hello, World!");
Global Deno namespaces expose APIs that are not available in the browser.
An implementation of the Unix cat program: [1]
/**
* cat.ts
*/
for (const filename of Deno.args) {
const file = await Deno.open(filename);
await file.readable.pipeTo(Deno.stdout.writable, { preventClose: true });
}
A simple Web server: [2]
Deno.serve((req) => new Response("hello world"));
Deno automatically downloads and caches the remote standard library files when the script is run, and then compiles the code.
Similarly, it can run a standard library script (such as a file server) directly without explicitly downloading, by providing the URL as the input filename (-A turns on all permissions):
$ deno run -A https://deno.land/std/http/file_server.ts
Download https://deno.land/std/http/file_server.ts
Compile https://deno.land/std/http/file_server.ts
...
HTTP server listening on http://0.0.0.0:4500/
References
edit- ^ a b Ryan Dahl, Bert Belder (2021-03-29). "Announcing the Deno Company".
- ^ "Contributors, denoland/deno, Github". GitHub. Retrieved 5 July 2019.
- ^ "Release 2.1.1". 21 November 2024. Retrieved 22 November 2024.
- ^ "deno/LICENSE at main". GitHub. Retrieved 5 July 2019.
- ^ a b c d "Deno Manual". deno.com. Retrieved 2019-05-17.
- ^ Schiemann, Dylan (December 26, 2018). "Deno: Secure V8 TypeScript Runtime from Original Node.js Creator". InfoQ. Archived from the original on May 17, 2019. Retrieved May 17, 2019.
- ^ Paul Krill (2018-06-21). "Ryan Dahl's Node.js regrets lead to Deno". InfoWorld. Archived from the original on 2019-04-14.
- ^ Dahl, Ryan (2018-06-06). 10 things I regret about Node.js. JSConf EU. Retrieved 2019-05-17 – via YouTube.
- ^ Dahl, Ryan (2018-06-06). "Design mistakes in Node" (PDF). Github.
- ^ "denoland/deno, branch "golang"". Github.
- ^ "Suggestion: Look into porting to Rust and using Tokio". GitHub.
- ^ "Tokio - The asynchronous run-time for the Rust programming language". Tokio.rs.
- ^ "Protobuf seems like a lot of overhead for this use case?". Github.
- ^ "Remove flatbuffers". GitHub.
- ^ "Replace flatbuffers". GitHub. April 15, 2019. Retrieved July 11, 2019.
- ^ "denoland/deno_std: deno standard modules". Github. 3 March 2022.
- ^ "Deno 1.0". deno.com. Retrieved 2020-05-14.
- ^ Dahl, Ryan (4 May 2022). "JavaScript Containers". tinyclouds.org. Archived from the original on 4 May 2022.
- ^ Krill, Paul (2021-06-24). "Deno Company unveils server-side JavaScript hosting service". InfoWorld. Archived from the original on 27 Jun 2022. Retrieved 2022-04-14.
- ^ Krill, Paul (2022-06-03). "Deno Deploy moves toward GA, adds paid plan". InfoWorld. Retrieved 2022-07-24.
- ^ Luca, Casonato (2022-07-22). "Introduction Fresh 1.0 as new full stack web framework for Deno". Deno Blog. Retrieved 2022-07-24.
- ^ Casonato, Luca (2022-09-08). "Fresh 1.1 - automatic JSX, plugins, DevTools, and more". Deno Blog. Retrieved 2022-09-10.
- ^ Jiang, Andy (2023-04-04). "Announcing Deno SaaSKit: an open-source SaaS template built with Fresh". Deno Blog. Retrieved 2022-04-04.
- ^ "Announcing Deno 2". Deno Blog. 2024-10-09. Retrieved 2024-10-27.
- ^ "Deno Is Ready for Production". InfoQ. Retrieved 2020-07-01.
- ^ "Modules: ECMAScript modules | Node.js v17.6.0 Documentation".
- ^ "Deno - A modern runtime for JavaScript and TypeScript".
- ^ "Modules: ECMAScript modules | Node.js v17.6.0 Documentation".
- ^ "Deno - A modern runtime for JavaScript and TypeScript".
- ^ "Deno.js in Production. Key Takeaways". Medium.com. Retrieved 16 May 2022.
- ^ "Documentation". GitHub. 3 March 2022.
- ^ "Deno raises $21M". deno.com. Archived from the original on 22 June 2022.
- ^ "Releases". GitHub. 2020-12-30. Retrieved 2021-01-14.
- ^ "Releases".
- ^ "Releases".