I have installed several proxy programs whose IP addresses are, for example, 127.0.0.1:8580, 127.0.0.1:9966, 127.0.0.1:7070. You may regrard them as Tor and its alternatives.
You know, certain proxy programs are faster than others at times, while at other times, they would be slower.
As far as I have used, The Firefox add-in, AutoProxy and FoxyProxy Standard, can define a list of rules such as any urls matching the pattern *.google.com should be proxied to 127.0.0.1:8580. But the rule is "static". I want *.google.com to be proxied to the fastest proxy, no matter which one.
To sum up, I'm seeking a program/Firefox addin/mechanism that proxies any defined urls to the fastest proxy address amony a defined list.