OWASP

OWASP is a non profit organization that is dedicated to improving the security of software. They lead open-source software efforts, hold events for developers to learn more about security, and are well respected in the software community.

They are well-known for the OWASP Top 10 - a list that they create to talk about the most common, most important vulnerabilities that they see during their work throughout a given year. A new list is published every year as they try to continue moving the security world forward.

For more information, see Open Web Application Security Project.