A HTTP Proxy list updating service for Google App Engine.
http://free-proxy-list.appspot.com/proxy.json
{"Host":"200.35.187.114","Port":8080,"Type":3,"Anonymous":1}
{"Host":"83.128.112.158","Port":80,"Type":1,"Anonymous":0}...
$ /YOUR_APP_ENGINE_PATH/appcfg.py update proxylist