SPIZD stands for Stress Probing Invasive Zap Destructor; it's a command-line stress test tool used to determine how many simultaneous (concurrent) connections servers can handle. Protocols: http, pop3, pop3s, imap, imaps, smtp, smtps, ssh, radius.
Death Star is a 'multi-protocol stress testing' tool. Initially forked from LOIQ v0.3a, Death Star seeks to surpass LOIC and LOIQ in terms of performance, OS support and win.