This is RATS, a rough auditing tool for security, originally developed by Secure Software Inc. It is a tool for scanning C, C++, Perl, PHP, Python (and soon Ruby) source code and flagging common security related programming errors such as buffer overflows and TOCTOU (Time Of Check, Time Of Use) race conditions. As its name implies, the tool performs only a rough analysis of source code. It will not find every error and will also find things that are not errors. Manual inspection of your code is still necessary, but greatly aided with this tool.