Looks like Microsoft will stop supporting IE11 for most of it’s web apps by August 2021.
In the past, we’ve dropped support for browsers when the browser vendor has “end-of-life” it. IE11 is somewhat weird because it shipped with Windows 10 and Microsoft has since adopted a Windows-as-a-service model. Since there’s no Windows 11 on the horizon and Windows 10 will receive updates for the indefinite future, this would in theory mean Microsoft will keep supporting IE11 as well.
Still, if the two-hundred-billion-dollar-multinational doesn’t think it’s worthwhile supporting it’s own legacy browser for its flag ship products, one might wonder why Silverstripe CMS should.
An important note, that this would only apply to the back end part of the Silverstripe CMS. The front end of your site can be targeted to whichever browser you want.
I’m curious, if there’s still much demand for using the CMS with IE11?
Dropping support for IE11 would reduce our maintenance burden and make it easier to develop new UI features. It would also allow us to adopt new JS libraries, although most of the key libraries we use have good IE11 support. A nice side benefit is that would could transpile our JS libraries to ES6 directly and remove a bunch of polyfill which would hopefully reduce the size of our bundles.