generated: '2026-07-20'
method: searched
source: >-
  https://registry.npmjs.org/@microsoft/mixed-reality-extension-sdk,
  https://registry.npmjs.org/@microsoft/mixed-reality-extension-altspacevr-extras,
  https://registry.npmjs.org/altspacevr-behaviors,
  https://github.com/microsoft/mixed-reality-extension-sdk,
  https://github.com/AltspaceVR/AltspaceSDK
description: >-
  Client libraries published for AltspaceVR. AltspaceVR was acquired by
  Microsoft in 2017 and the platform was permanently shut down on 2023-03-10,
  so every package below is END-OF-LIFE and its source repository is archived
  on GitHub. They are recorded here as the historical, verifiable developer
  surface of the platform, not as a live integration path. Verified against the
  npm registry (registry.npmjs.org) and the GitHub REST API on 2026-07-20; the
  latest real publish of the Mixed Reality Extension SDK was 0.21.0 on
  2021-04-08.
status: end-of-life
platform_shutdown: '2023-03-10'
packages:
  - language: javascript
    registry: npm
    name: "@microsoft/mixed-reality-extension-sdk"
    url: https://www.npmjs.com/package/@microsoft/mixed-reality-extension-sdk
    source: https://github.com/microsoft/mixed-reality-extension-sdk
    install: npm install @microsoft/mixed-reality-extension-sdk
    official: true
    license: MIT
    latest_version: 0.21.0
    first_published: '2018-12-04'
    last_published: '2021-04-08'
    archived: true
    status: end-of-life
    note: >-
      The Mixed Reality Extension (MRE) SDK let developers build server-hosted
      3D world extensions for AltspaceVR in Node.js. Source repo archived by
      Microsoft (last push 2022-04-09).
  - language: javascript
    registry: npm
    name: "@microsoft/mixed-reality-extension-altspacevr-extras"
    url: https://www.npmjs.com/package/@microsoft/mixed-reality-extension-altspacevr-extras
    source: https://github.com/microsoft/mixed-reality-extension-sdk
    install: npm install @microsoft/mixed-reality-extension-altspacevr-extras
    official: true
    license: MIT
    latest_version: 0.20.0
    archived: true
    status: end-of-life
    note: >-
      Companion package exposing AltspaceVR-specific host behaviors to MRE
      developers.
  - language: javascript
    registry: npm
    name: altspacevr-behaviors
    url: https://www.npmjs.com/package/altspacevr-behaviors
    source: https://github.com/NGenesis/altspacevr-behaviors
    install: npm install altspacevr-behaviors
    official: false
    license: MIT
    latest_version: 1.1.5
    first_published: '2018-07-11'
    last_published: '2018-09-03'
    status: end-of-life
    note: >-
      Third-party (community, npm maintainer "ngenesis") helper behaviors and
      A-Frame components for the older AltspaceSDK. Not published by
      AltspaceVR or Microsoft.
source_repositories:
  - name: AltspaceVR/AltspaceSDK
    url: https://github.com/AltspaceVR/AltspaceSDK
    description: Software Development Kit for AltspaceVR (the original, pre-MRE web/A-Frame SDK)
    license: MIT
    stars: 162
    archived: true
    homepage: https://developer.altvr.com/
    note: Homepage developer.altvr.com no longer resolves (DNS failure probed 2026-07-20).
  - name: microsoft/mixed-reality-extension-sdk
    url: https://github.com/microsoft/mixed-reality-extension-sdk
    stars: 142
    archived: true
  - name: microsoft/mixed-reality-extension-sdk-samples
    url: https://github.com/microsoft/mixed-reality-extension-sdk-samples
    stars: 93
    archived: true
  - name: microsoft/mixed-reality-extension-unity
    url: https://github.com/microsoft/mixed-reality-extension-unity
    stars: 61
    archived: true
    description: Unity library for adding MRE user-generated-content capability to host apps