jQuery.browser http://api.jquery.com/jQuery.browser/

jquery.browser.js.coffee

# Restores `$.browser` functionality removed in jQuery 1.9
jQuery.uaMatch = (ua) ->
  ua = ua.toLowerCase()
  match = /(chrome)[ \/]([\w.]+)/.exec(ua) or
          /(webkit)[ \/]([\w.]+)/.exec(ua) or
          /(opera)(?:.*version|)[ \/]([\w.]+)/.exec(ua) or
          /(msie) ([\w.]+)/.exec(ua) or
          ua.indexOf("compatible") < 0 and /(mozilla)(?:.*? rv:([\w.]+)|)/.exec(ua) or []
  browser: match[1] or ''
  version: match[2] or '0'

matched = jQuery.uaMatch(navigator.userAgent)
browser = {}
if matched.browser
  browser[matched.browser] = true
  browser.version = matched.version

if browser.chrome
  browser.webkit = true
else if browser.webkit
  browser.safari = true
jQuery.browser = browser