This issue is a placeholder for discussion regarding Moodle officially dropping support for all versions of Internet Explorer.

At time of writing, the only supported version of Internet Explorer is IE11.

According to the Lifecycle FAQ:

1. Microsoft recommends using Edge
2. Edge has backwards compatibility support for IE 11

IE11 is only suported on:

1. Windows 8.1 Update
2. Windows 10
3. Windows Server 2012
4. Windows Server 2012 R2
5. Windows Server 2016 and subsequent releasess
6. Windows Embedded Standard 7
7. Windows Embedded POSReady 7
8. Windows Thin PC
9. Windows Embedded 8 Standard
10. Windows 8.1 Industry Update

Many other organisations have already taken this step, including:

1. YouTube
2. Google
3. Atlassian
4. Wix

Technologically IE11 is the browser causing us most grief and requiring us to polyfill the most.

I would like to propose that we:

1. drop official support for IE 11 as soon as possible - preferably in Moodle 3.9
2. In Moodle 3.9 we:
   1. do not remove any supporting functionality yet
   2. continue to actually offer all polyfills and test in IE11
   3. display an in-browser warning that support for IE11 and older will be removed soon
3. In Moodle 4.0 we:
   1. stop testing for IE in 4.0
4. In Moodle 4.3 (next LTS after 3.9) we:
   1. remove polyfills in 4.3

Why so soon?

1. Due to the 4.0 roadmap, 3.9 will likely be in support for an extended period
2. It is getting harder and harder to develop for all versions of IE
3. IE supports a rapidly diminishing percentage of market share yet still has a high cost to development (i.e. testing, polyfills, etc.)
4. Microsoft recommend using Edge instead of IE11