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Ecma TC39

Ecma International, Technical Committee 39 - ECMAScript

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TC39

Ecma International's TC39 is a group of JavaScript developers, implementers, academics, and more, collaborating with the community to maintain and evolve the definition of JavaScript.

Contribute

TC39 welcomes contributions from the JavaScript community, whether it is feedback on existing proposals, improved documentation, testing, implementations, or even language feature ideas. See our contributor guide for details.

Important

To participate in TC39 meetings as a member, join Ecma.

Specifications

We develop the JavaScript (formally, ECMAScript) specification, the Internationalization API specification, the Source Map specification, and, of course, JSON! We meet every two months to discuss proposals. To learn more about the process, please take a look at the six stages for new language feature proposals. See our meeting agendas and minutes to learn more.

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  1. ecma262 ecma262 Public

    Status, process, and documents for ECMA-262

    HTML 15.5k 1.4k

  2. ecma402 ecma402 Public

    Status, process, and documents for ECMA 402

    HTML 585 113

  3. test262 test262 Public

    Official ECMAScript Conformance Test Suite

    JavaScript 2.6k 508

  4. proposals proposals Public

    Tracking ECMAScript Proposals

    19k 741

  5. agendas agendas Public

    TC39 meeting agendas

    JavaScript 1.2k 199

  6. notes notes Public

    TC39 meeting notes

    JavaScript 693 127

Repositories

Showing 10 of 308 repositories
  • agendas Public

    TC39 meeting agendas

    tc39/agendas’s past year of commit activity
    JavaScript 1,161 199 0 5 Updated Nov 8, 2025
  • proposal-async-context Public

    Async Context for JavaScript

    tc39/proposal-async-context’s past year of commit activity
    HTML 783 CC0-1.0 24 22 5 Updated Nov 8, 2025
  • ecma262 Public

    Status, process, and documents for ECMA-262

    tc39/ecma262’s past year of commit activity
  • dataset Public

    The automatic track tc39 proposals

    tc39/dataset’s past year of commit activity
    TypeScript 45 Unlicense 13 2 0 Updated Nov 8, 2025
  • ecma402 Public

    Status, process, and documents for ECMA 402

    tc39/ecma402’s past year of commit activity
    HTML 585 113 157 13 Updated Nov 7, 2025
  • notes Public

    TC39 meeting notes

    tc39/notes’s past year of commit activity
    JavaScript 693 127 1 (1 issue needs help) 7 Updated Nov 7, 2025
  • proposal-temporal Public

    Provides standard objects and functions for working with dates and times.

    tc39/proposal-temporal’s past year of commit activity
    HTML 3,615 172 37 10 Updated Nov 7, 2025
  • test262 Public

    Official ECMAScript Conformance Test Suite

    tc39/test262’s past year of commit activity
    JavaScript 2,622 508 213 (4 issues need help) 68 Updated Nov 7, 2025
  • proposal-await-dictionary Public

    A proposal to add Promise.allKeyed to ECMAScript

    tc39/proposal-await-dictionary’s past year of commit activity
    JavaScript 94 MIT 7 6 0 Updated Nov 7, 2025
  • proposal-intl-era-monthcode Public

    To specify necessary details about era, eraYear and monthCode usage with Temporal for non-ISO calendars.

    tc39/proposal-intl-era-monthcode’s past year of commit activity
    HTML 4 MIT 8 13 3 Updated Nov 7, 2025