The Common Open Research Emulator (CORE) is a tool for emulating networks on one or more machines. You can connect these emulated networks to live networks. CORE consists of a GUI for drawing topologies of lightweight virtual machines, and Python modules for scripting network emulation.
Proxy Tester is a proxy list tester and then it generates a wpad.dat file you can use for your browser based on working servers. wpad.dat file selects a random proxy server from the list of provided working proxy servers with each connection request.