What organization provides guidance on developing trustworthy and secure software applications?

The organization that provides guidance on developing trustworthy and secure software applications is the Open Web Application Security Project (OWASP). OWASP is a renowned nonprofit organization focused on improving the security of software. It achieves this by creating freely available resources such as guidelines, research, and tools aimed at enhancing software security practices.

OWASP is particularly well-known for its Top Ten project, which outlines the most critical web application security risks, offering developers a clear direction for vulnerability mitigation. The organization emphasizes education and awareness, providing best practices and comprehensive resources that can help create secure development processes and applications.

While other options might provide some level of resources or guidelines concerning software security, OWASP stands out specifically for its extensive focus on web application security and the practical guidance it offers to organizations and developers seeking to implement robust security measures during the software development lifecycle.