SING stands for 'Send ICMP Nasty Garbage'. It is a tool that sends ICMP packets fully customized from command line. Its main purpose is to replace the ping command but adding certain enhancements (Fragmentation, spoofing,...)
Pace-IDS is an Intrusion Detection system designed to replace Tripwire, in that it is faster, and more effective of detecting trojan activity, and is easier to configure. All you have to do usually is simply change one variable to your email address.