Latest Firefox 20 user agents:

User Agent Platform Device
Mozilla/5.0 (X11; Ubuntu; Linux i686 on x86_64; rv:20.0) Gecko/20100101 Firefox/20.0 Ubuntu Unknown
Mozilla/5.0 (X11; Ubuntu; Linux armv7l; rv:20.0) Gecko/20100101 Firefox/20.0 Ubuntu Unknown
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.3) Gecko/20100423 Ubuntu/10.04 (lucid) Firefox/20.6.3 Ubuntu 10 Unknown
Mozilla/5.0 (X11; Linux; Linux x86_64; rv:20.0) Gecko/20100101 Firefox/20.0 GNU/Linux Unknown
Mozilla/5.0 (X11; FreeBSD amd64; rv:20.0) Gecko/20100101 Firefox/20.0 FreeBSD Unknown
Mozilla/5.0 (Windows NT.6.2; WOW64) Gecko/20082704 Firefox/20.0 Windows NT Unknown
Mozilla/5.0 (Windows NT.6.2; WOW64) Gecko/20042012 Firefox/20.0 Windows NT Unknown
Mozilla/5.0 (Windows NT.6.2; Win64; x64) Gecko/20103111 Firefox/20.0 Windows NT Unknown
Mozilla/5.0 (Windows NT.6.2; Win64; x64) Gecko/20101006 Firefox/20.0 Windows NT Unknown
Mozilla/5.0 (Windows NT.6.2; Win64; x64) Gecko/20092504 Firefox/20.0 Windows NT Unknown
Mozilla/5.0 (Windows NT.6.2; Win64; x64) Gecko/20070405 Firefox/20.0 Windows NT Unknown
Mozilla/5.0 (Windows NT.6.2; Win64; x64) Gecko/20070105 Firefox/20.0 Windows NT Unknown
Mozilla/5.0 (Windows NT.6.2; Win64; x64) Gecko/20042710 Firefox/20.0 Windows NT Unknown
Mozilla/5.0 (Windows NT.6.2; Win64; x64) Gecko/20033101 Firefox/20.0 Windows NT Unknown
Mozilla/5.0 (Windows NT.6.2; Win64; x64) Gecko/20021801 Firefox/20.0 Windows NT Unknown
Mozilla/5.0 (Windows NT.6.2; Win64; x64) Gecko/20011504 Firefox/20.0 Windows NT Unknown
Mozilla/5.0 (Windows NT 6.3; Win64; x64) Gecko/20050906 Firefox/20.0 Windows 8 Unknown
Mozilla/5.0 (Windows NT 6.2; WOW64; rv:5.0) Gecko/20100101 Firefox/20.0 Windows 8 Unknown
Mozilla/5.0 (Windows NT 6.2; WOW64; rv:45.0) Gecko/20100101 Firefox/20.0 Windows 8 Unknown
Mozilla/5.0 (Windows NT 6.2; WOW64; rv:20.0) Gecko/20130206 Firefox/20.0 Windows 8 Unknown