LOIC (short for Low Orbit Ion Cannon) is a free and open-source network/website stress testing tool initially developed by Praetox Technologies (currently maintained by the open source community) with C# in 2014. It's made for educational purposes only (that's to say, you should not use this software for illegal or unethical purposes, including activities that give rise to criminal or civil liability), and intended to help server owners develop a "hacker defense" attitude.