An anonymous reader writes "Mozilla on Tuesday officially launched Firefox 21 for Windows, Mac, Linux, and Android. Improvements include the addition of multiple social providers on the desktop as well as open source fonts on Android. In the changelog, the company included an interesting point that's worth elaborating on: 'Preliminary implementation of Firefox Health Report.' Mozilla has revealed that FHR so far logs 'basic health information' about Firefox: time to start up, total running time, and number of crashes. Mozilla says the initial report is pretty simple but will grow 'in the coming months.' You can get it now from Mozilla."