Home-grown applications and services are increasingly being implemented in order to suit corporate and invidual needs. These custom applications and services are also succepitble to vulnerabilities which must be scanned for quickly and effectively. In addition, closed source scanning tool vendors often do not release checks for vulnerabilities until its too late, and these costly scanning tools do not offer vulnerability checks against custom-made applications and services that may be widely deployed by a corporation. In order to cope with this, individuals and companies are forced to develop their own scanning tools in order to quickly scan for and identify vulnerabilities. This talk will offer solutions against developing scanning tools from scratch. There is no need to re-invent the wheel when open source tools such as Nessus, Hydra, and Nmap are flexible enough to allow for their functionality to be extended by offering appropriate API and plugin functionality. This talk will teach the audience how to develop custom plugins for these popular tools in order to accomplish custom vulnerability scanning and enumeration needs.