Release lifecycle docs overhaul & simplification

source/_static/badges/allplans-cloud-selfhosted.md

@@ -0,0 +1,11 @@
+```{raw} html
+<div class="mm-plans-badge">
+```
+
+![plans-img](../_static/images/badges/flag_icon.svg) Available on [all plans](https://mattermost.com/pricing/)
+
+!|deployment-img| [Cloud](https://mattermost.com/sign-up/) and [self-hosted](https://mattermost.com/deploy/) deployments
+
+```{raw} html
+</div>
+```

source/_static/badges/allplans-selfhosted.md

@@ -0,0 +1,11 @@
+```{raw} html
+<div class="mm-plans-badge">
+```
+
+![plans-img](../_static/images/badges/flag_icon.svg) Available on [all plans](https://mattermost.com/pricing/)
+
+![deployment-img](../_static/images/badges/deployment_icon.svg) [self-hosted](https://mattermost.com/deploy/) deployments
+
+```{raw} html
+</div>
+```

source/_static/badges/ent-only.md

@@ -0,0 +1,12 @@
+```{raw} html
+<div class="mm-plans-badge">
+```
+
+![plans-img](../_static/images/badges/flag_icon.svg) Available only on [Enterprise](https://mattermost.com/pricing/) plans
+
+```{raw} html
+</div>
+```
+
+
+

source/deploy/desktop-app-changelog.rst

@@ -1,5 +1,5 @@
-Desktop application changelog
-==============================
+Desktop app changelog
+=====================
 
 This changelog summarizes updates to Mattermost desktop app releases for `Mattermost <https://mattermost.com>`__.
 

source/guides/client-compatibility.rst

@@ -0,0 +1,18 @@
+Client compatibility
+=====================
+
+all plans; cloud & self-hosted
+
+what this section is about and who it's for
+
+see also: release lifecycle
+
+.. toctree::
+   :maxdepth: 1
+   :hidden:
+   :titlesonly:
+
+   Desktop app </collaborate/access-your-workspace>
+   Mobile app
+
+* :doc:`Access your Mattermost workspace </collaborate/access-your-workspace>` - Log in to a Mattermost workspace to connect with your teammates.

source/guides/deployment.rst

@@ -11,6 +11,7 @@ Learn how to install, deploy, and scale Mattermost for teams and organizations o
   :hidden:
   :titlesonly:
 
+    Release life cycle </guides/release-lifecycle>
     Prepare your Mattermost database </install/prepare-mattermost-database>
     Deploy on Ubuntu </install/install-ubuntu>
     Deploy using Docker </install/install-docker>
@@ -35,6 +36,7 @@ Learn how to install, deploy, and scale Mattermost for teams and organizations o
 
   * Encountering issues with your deployment? See the :ref:`Deployment Troubleshooting <install/troubleshooting:deployment troubleshooting>` or :doc:`high scale troubleshooting </deploy/high-scale-troubleshoot>` documentation for details.
 
+* :doc:`Matermost release lifecycle </guides/release-lifecycle>` - Learn about Mattermost releases, and our recommended practices around deployment updates and ESRs.
 * :doc:`Prepare your Mattermost database </install/prepare-mattermost-database>` - Learn how to prepare and configure a database for Mattermost.
 * :doc:`Deploy on Ubuntu </install/install-ubuntu>` - Signed packages direct from Mattermost featuring a single command for install and upgrades.
 * :ref:`Deploy using Docker <install/install-docker:deploy mattermost on docker for production use>` - The fastest way to try Mattermost and a great single server installation option.

source/guides/release-lifecycle.rst

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+Release lifecycle
+=================
+
+.. include:: ../_static/badges/allplans-selfhosted.rst
+  :start-after: :nosearch:
+
+.. important::
+
+  **Support for Mattermost Server v8.1 Extended Support Release has come to the end of its life cycle on May 15, 2024. Upgrading to Mattermost Server v9.5 Extended Support Release or later is required.**
+
+.. toctree::
+   :maxdepth: 1
+   :hidden:
+   :titlesonly:
+
+   Mattermost release policy </lifecycle/release-policy>
+   Mattermost Server releases </lifecycle/mattermost-server-releases>
+   Mattermost v9 changelog </deploy/mattermost-v9-changelog>
+   Unsupported legacy releases </deploy/unsupported-legacy-releases>
+   Server version archive </lifecycle/version-archive>
+   Desktop app releases <need path>
+   Desktop app changelog </deploy/desktop-app-changelog>
+   Mobile apps release <need path>
+   Mobile apps changelog </deploy/mobile-app-changelog>
+
+* :doc:`Mattermost release policy </lifecycle/release-policy>` - Learn about Mattermost’s release policy, and our recommended practices around deployment updates and ESRs.
+* :doc:`Mattermost server releases </lifecycle/mattermost-server-releases>` - Learn more about supported Mattermost server releases.
+* :doc:`Mattermost v9 changelog </deploy/mattermost-v9-changelog>` - Learn more about what's new and changed in Mattermost v9 releases.
+* :doc:`Unsupported legacy releases </deploy/unsupported-legacy-releases>` - Learn what changed in legacy Mattermost releases that are no longer supported.
+* :doc:`Version archive </lifecycle/version-archive>` - Confirm the version of Mattermost Server you're using is official by its signature.
+* :doc:`Desktop app releases <need path>` - Learn more about supported Mattermost desktop app releases.
+* :doc:`Desktop app changelog </deploy/desktop-app-changelog>` - Learn more about what's new and changed in Mattermost desktop app releases.
+* :doc:`Mobile apps <need path>` - Learn more about supported Mattermost mobile app releases.
+* :doc:`Mobile apps changelog </deploy/mobile-app-changelog>` - Learn more about what's new and changed in Mattermost mobile app releases.
+
+

source/lifecycle/mattermost-server-releases.md

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+# Mattermost Server releases
+
+```{include} ../_static/badges/allplans-selfhosted.md
+```
+
+```{Important}
+**Support for Mattermost Server v8.1 Extended Support Release has come to the end of its life cycle on May 15, 2024. Upgrading to Mattermost Server v9.5 Extended Support Release or later is required.**
+```
+
+## Frequency
+Mattermost releases a new server version on the 16th of each month in [binary form](/upgrade/upgrading-mattermost-server). See the [Mattermost v9 changelog](/deploy/mattermost-v9-changelog) for details on v9.x server releases, and [unsupported Mattermost legacy releases](/deploy/unsupported-legacy-releases) for older Mattermost releases.
+
+## Latest releases
+
+| **Release** | **Life cycle start** | **Life cycle end** |
+|:---|:---|:---|
+| v9.8 {ref}`FEATURE <release-types>` \| [Download](https://releases.mattermost.com/9.8.0/mattermost-9.8.0-linux-amd64.tar.gz) \| {ref}`Changelog <release-v9-8-feature-release>` | 2024-05-16 | 2024-08-15 |
+| v9.7 {ref}`FEATURE <release-types>` \| [Download](https://releases.mattermost.com/9.7.3/mattermost-9.7.3-linux-amd64.tar.gz) \| {ref}`Changelog <release-v9-7-feature-release>` | 2024-04-16 | 2024-07-15 |
+| v9.6 {ref}`FEATURE <release-types>` \| [Download](https://releases.mattermost.com/9.6.2/mattermost-9.6.2-linux-amd64.tar.gz) \| {ref}`Changelog <release-v9-6-feature-release>` | 2024-03-16 | 2024-06-15 |
+| v9.5 {ref}`EXTENDED <release-types>` \| [Download](https://releases.mattermost.com/9.5.4/mattermost-9.5.4-linux-amd64.tar.gz) \| {ref}`Changelog <release-v9-5-extended-support-release>` | 2024-02-16 | 2024-11-15 |
+| v9.4 {ref}`FEATURE <release-types>` \| [Download](https://releases.mattermost.com/9.4.5/mattermost-9.4.5-linux-amd64.tar.gz) \| {ref}`Changelog <release-v9-4-feature-release>` | 2024-01-16 | 2024-04-15 |
+| v9.3 {ref}`FEATURE <release-types>` \| [Download](https://releases.mattermost.com/9.3.3/mattermost-9.3.3-linux-amd64.tar.gz) \| {ref}`Changelog <release-v9-3-feature-release>` | 2023-12-16 | 2024-03-15 |
+| v9.2 {ref}`FEATURE <release-types>` \| [Download](https://releases.mattermost.com/9.2.6/mattermost-9.2.6-linux-amd64.tar.gz) \| {ref}`Changelog <release-v9-2-feature-release>` | 2023-11-16 | 2024-02-15 |
+| v9.1 {ref}`FEATURE <release-types>` \| [Download](https://releases.mattermost.com/9.1.5/mattermost-9.1.5-linux-amd64.tar.gz) \| {ref}`Changelog <release-v9-1-feature-release>` | 2023-10-16 | 2024-01-15 |
+| v9.0 {ref}`MAJOR <release-types>` \| [Download](https://releases.mattermost.com/9.0.5/mattermost-9.0.5-linux-amd64.tar.gz) \| {ref}`Changelog <release-v9-0-major-release>` | 2023-09-16 | 2023-12-15 |
+|  |  |  |

source/lifecycle/release-policy.md

@@ -0,0 +1,58 @@
+# Release policy
+
+```{include} ../_static/badges/allplans-selfhosted.md
+```
+
+This page describes Mattermost’s release policy, and our recommended practices around releases, including extended support releases, so that you can allocate your IT resources effectively.
+
+To ensure a secure, functional, performant, and efficient Mattermost deployment, system admins managing a self-hosted deployment need to be proactive in:
+- monitoring Mattermost release cycles and planning upgrades before life cycles end,
+- considering the use of [extended support releases](#extended-support-releases) for longer-term stability, and
+- keeping both server and client applications updated.
+
+(release-types)=
+## Release types
+
+Mattermost releases include feature, extended support, and major releases. Each release has a specified life cycle start and end date, and life cycles depend on the release type. 
+
+- **Feature**: Feature releases contain new features and include high severity and high impact security backported to the previous 3 monthly releases. This is to ensure your organization's Mattermost deployment remains secure and stable. It's crucial to apply feature updates to maintain the security of your Mattermost deployment.
+- **Extended**: Releases maintained for a longer period of time that receive backports for security fixes and major bug fixes for the length of their life cycle. Learn more about [Mattermost extended support releases](#extended-support-releases) below.
+- **Major**: Annual mid-year releases that follow a release theme, and include multiple new features.
+
+With multiple release types, you can plan the upgrade path that best suits your organization's needs and compliance requirements. Align your plan with your organization's IT strategy and risk management policies to ensure continuous operation without exposure to security vulnerabilities.
+
+See the full list of all Mattermost Server and desktop app releases and life cycles.
+
+(extended-support-releases)=
+## Extended support releases
+
+```{include} ../_static/badges/ent-only.md
+```
+
+Mattermost Extended Support Releases (ESRs) are a strategic choice for organizations looking for stability and reduced frequency of updates. Using ESRs can minimize disruptions associated with frequent upgrades, making them an attractive option for environments where stability is paramount. New ESRs are released twice a year, every February and August release. An ESR is supported for nine months to provide customers with enough time to test and upgrade to the next ESR.
+
+We strongly recommend planning ahead for upgrades before the end of an ESR's life cycle to ensure continuity in receiving security updates.
+
+ESRs don’t include changes to product functionality or new features. ESRs are intended for organizations who value stability over having the newest features and improvements, or who have a long internal testing and certification process to undergo when upgrading. Consider using ESRs for more stable and long-term deployments, especially in environments where frequent updates are challenging. If your organization prefers to have the newest features and improvements, Extended Support Releases may not be the best fit for you.
+
+See the full list of all Mattermost Server and desktop app releases and life cycles, including extended support releases. To install extended support releases, follow our [install](https://docs.mattermost.com/guides/deployment.html) or [upgrade](https://docs.mattermost.com/upgrade/upgrading-mattermost-server.html) documentation. 
+
+```{Important}
+We strongly recommend reviewing [upgrade best practices](https://docs.mattermost.com/upgrade/prepare-to-upgrade-mattermost.html#upgrade-best-practices) for upgrading, and [important upgrade notes](/upgrade/important-upgrade-notes) for all the versions beyond the current ESR version you have currently installed. See the [Mattermost v9 changelog](/deploy/mattermost-v9-changelog) for a list of database, API, and `config.json` updates for all v9.x releases.
+```
+
+![Timeline-based chart showing the lifecycle of Mattermost Extended Support Releases and feature releases from last year and this year.](../images/ESR_graphic2.png)
+
+(esr-notifications)=
+### ESR Notifications
+
+```{include} ../_static/badges/ent-only.md
+```
+
+When an ESR is at the end of its life cycle, there will be announcements ahead of time to provide time for people to test, certify, and deploy a newer ESR version before support ends. After a release reaches its end-of-life, no further updates will be provided for that version. 
+
+To receive updates about Extended Support Releases, sign up for [our mailing list](https://eepurl.com/dCKn2P).
+
+For a new upcoming ESR, an email is sent out 3 months before the end of support for an ESR version. This email includes a note about the new ESR that was just published. A second email is sent out during the month when an ESR version is reaching the end of support.
+
+For deprecated ESRs, an email announcement is sent 3 months in advance. We also add reminders on our release announcements, changelogs, important upgrade notes, and the [Mattermost Discussion Forums](https://forum.mattermost.com/) site.