docs: remove links to Slack and deleted OC tiers

The Discord server is a better alternative to Slack, with a very active
community. The Slack channel also lost its history, so there isn't
anything interesting left.

The sponsorship tiers on OpenCollective have been deleted. The current
balance will comfortably cover future expenses and there hasn't been any
interest from non-shady organizations or developers that actually use
the library.

.github/ISSUE_TEMPLATE/ask-a-question.yml

@@ -7,7 +7,7 @@ body:
       value: |
         Ask anything about developing LWJGL applications or the development of LWJGL itself!
 
-        However, questions regarding native API usage (e.g. how do I do X in OpenGL?) are out of scope. Try the Forum/Slack/Discord links, you'll find plenty of people willing to help.
+        However, questions regarding native API usage (e.g. how do I do X in OpenGL?) are out of scope. Try the Discord/Forum links, you'll find plenty of people willing to help.
 
         Finally, try searching the existing issues first, your question may have been answered already.
   - type: textarea

.github/ISSUE_TEMPLATE/config.yml

@@ -1,17 +1,11 @@
 blank_issues_enabled: false
 contact_links:
-  - name: Forum
-    url: http://forum.lwjgl.org
-    about: The LWJGL forum, up since 2003.
-  - name: Slack
-    url: https://lwjgl.slack.com/
-    about: The LWJGL Slack workspace.
-  - name: Slack (join link)
-    url: http://slack.lwjgl.org/
-    about: Visit to join the LWJGL Slack workspace.
+  - name: Twitter
+    url: https://twitter.com/LWJGL
+    about: The official LWJGL account on Twitter.
   - name: Discord
     url: https://discord.gg/6CywMCs
     about: The LWJGL Discord server.
-  - name: Twitter
-    url: https://twitter.com/LWJGL
-    about: The official LWJGL account on Twitter.
+  - name: Forum
+    url: http://forum.lwjgl.org
+    about: The LWJGL forum, up since 2003.

BACKERS.md

@@ -7,53 +7,4 @@ Thank you to all the people who have contributed to LWJGL! [[Contribute](https:/
 
 Thank you to all our backers! [[Become a backer](https://opencollective.com/lwjgl#section-contribute)]
 
-### People
-
 ![Backers](https://opencollective.com/lwjgl/backers.svg?width=825)
-
-### Organizations
-
-![Sponsors](https://opencollective.com/lwjgl/sponsors.svg?width=825)
-
-## Sponsors
-
-Special thank you to our sponsors! [[Become a sponsor](https://opencollective.com/lwjgl#section-contribute)]
-
-### Bronze 🥉
-
-<a href="https://opencollective.com/lwjgl/tiers/bronze-sponsor/0/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/bronze-sponsor/0/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/bronze-sponsor/1/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/bronze-sponsor/1/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/bronze-sponsor/2/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/bronze-sponsor/2/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/bronze-sponsor/3/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/bronze-sponsor/3/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/bronze-sponsor/4/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/bronze-sponsor/4/avatar.svg"></a>
-
-### Silver 🥈
-
-<a href="https://opencollective.com/lwjgl/tiers/silver-sponsor/0/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/silver-sponsor/0/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/silver-sponsor/1/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/silver-sponsor/1/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/silver-sponsor/2/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/silver-sponsor/2/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/silver-sponsor/3/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/silver-sponsor/3/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/silver-sponsor/4/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/silver-sponsor/4/avatar.svg"></a>
-
-### Gold 🥇
-
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/0/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/0/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/1/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/1/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/2/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/2/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/3/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/3/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/4/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/4/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/5/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/5/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/6/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/6/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/7/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/7/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/8/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/8/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/9/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/9/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/10/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/10/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/11/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/11/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/12/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/12/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/13/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/13/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/14/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/14/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/15/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/15/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/16/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/16/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/17/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/17/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/18/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/18/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/19/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/19/avatar.svg"></a>

README.md

@@ -2,8 +2,6 @@
 [![API Javadoc](https://img.shields.io/badge/API-docs-blue.svg)](https://javadoc.lwjgl.org/)
 [![License](https://img.shields.io/badge/license-BSD-blue.svg?colorB=lightgray)](https://github.com/LWJGL/lwjgl3/blob/master/LICENSE.md)
 
-[![Backers on Open Collective](https://opencollective.com/lwjgl/backers/badge.svg)](#backers)
-[![Sponsors on Open Collective](https://opencollective.com/lwjgl/sponsors/badge.svg)](#sponsors)
 ![Size](https://img.shields.io/github/repo-size/LWJGL/lwjgl3.svg?label=size&colorB=lightgray)
 [![Build Status](https://img.shields.io/github/actions/workflow/status/LWJGL-CI/lwjgl3/CI.yml?branch=master)](https://github.com/LWJGL-CI/lwjgl3/actions/workflows/CI.yml)
 
@@ -32,10 +30,9 @@ Useful links:
 
 Contact:
 
-- [Forum](http://forum.lwjgl.org)
-- [Slack](https://lwjgl.slack.com/) (click [this](http://slack.lwjgl.org/) to join)
-- [Discord](https://discord.gg/6CywMCs)
 - [![Twitter Follow](https://img.shields.io/twitter/follow/LWJGL?style=social)](https://twitter.com/LWJGL)
+- [Discord](https://discord.gg/6CywMCs)
+- [Forum](http://forum.lwjgl.org)
 
 If you'd like to contribute, see [doc/README](https://github.com/LWJGL/lwjgl3/tree/master/doc)
 for a quick overview of the project structure, installation instructions and
@@ -202,31 +199,8 @@ Use of a binding is subject to the terms of the [corresponding license](https://
 
 ## Supporting this project
 
-LWJGL exists thanks to [all the people](https://github.com/LWJGL/lwjgl3/blob/master/BACKERS.md) who [contribute](https://github.com/LWJGL/lwjgl3/blob/master/.github/CONTRIBUTING.md) and back/sponsor our collective.
+LWJGL exists thanks to [all the people](https://github.com/LWJGL/lwjgl3/blob/master/BACKERS.md) who [contribute](https://github.com/LWJGL/lwjgl3/blob/master/.github/CONTRIBUTING.md) and donate to our collective.
 
 <a href="https://opencollective.com/lwjgl/donate" target="_blank">
     <img src="https://opencollective.com/lwjgl/donate/button@2x.png?color=white" width=300 />
-</a>
-
-Our gold sponsors:
-
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/0/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/0/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/1/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/1/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/2/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/2/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/3/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/3/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/4/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/4/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/5/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/5/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/6/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/6/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/7/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/7/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/8/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/8/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/9/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/9/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/10/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/10/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/11/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/11/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/12/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/12/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/13/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/13/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/14/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/14/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/15/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/15/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/16/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/16/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/17/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/17/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/18/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/18/avatar.svg"></a>
-<a href="https://opencollective.com/lwjgl/tiers/gold-sponsor/19/website" target="_blank"><img src="https://opencollective.com/lwjgl/tiers/gold-sponsor/19/avatar.svg"></a>
+</a>