Just found this one in my http logfile;
Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.111 Safari/537.36 OPR/27.0.1689.69
So one User Agent string mentioning 4 browsers (Mozilla, Safari, Chrome and finally Opera 27, which is the actual browser) and 3 rendering engines (Applewebkit, KHTML and Gecko)? There is a lot of web-history in those 127 characters.