Mariella Moon / Engadget:

Microsoft starts testing Windows Defender Application Guard extensions, which open untrusted web pages in a virtual container, for Chrome and Firefox  —  Microsoft has developed and started testing Windows Defender Application Guard extensions for both Chrome and Firefox to better protect enterprise PCs.

Microsoft starts testing Windows Defender Application Guard extensions, which open untrusted web pages in a virtual container, for Chrome and Firefox (Mariella Moon/Engadget)
Source: Tech Meme