Mozilla has launched an experiment where they change the Firefox browser user agent to a three-digit “Firefox/100″” version to see if it will break websites. Mozilla developers are investigating if anything breaks when they release Firefox Nightly version 100 in March 2022. A user agent is a string by a web browser that includes information about the software used
Source: and technologies that it uses. Mozilla has only encountered an issue when using Slack’s message popup menu for about four months.”