ESAPI (The OWASP Enterprise Security API) is a free, open source, web application security control library that makes it easier for programmers to write lower-risk applications. The ESAPI libraries are designed to make it easier for programmers to retrofit security into existing applications. The ESAPI libraries also serve as a solid foundation for new development.
AntiXSS helps you to protect your current applications from cross-site scripting attacks, at the same time helping you to protect your legacy application with its Security Runtime Engine. Working with customer and partner feedback, AntiXSS incorporates radically and innovatively rethought features, offering you a newer, more powerful weapon against the often employed cross-site scripting (XSS) attack.