Open Source PKI solutions
The OpenCA PKI Development Project is a collaborative effort to develop a robust, full-featured and Open Source out-of-the-box Certification Authority implementing the most used protocols with full-strength cryptography world-wide.
TJWS is an Open Source HTTP Server and Servlet container written in 100% Java. It's designed to be a light weight, high performing, secure, embeddable, extensible and flexible. Very small footprinted (~100K), CGI, J2EE/JSP compatible. Servlet spec 3.1
acWEB is an OpenSource replacement for MS IIS and other proprietary WEB servers for Windows. Unlike IIS, acWEB is not affected by viruses like CodeRed, Nimda, etc :).