Hans has helped shape the server-side Java landscape as an active member of several Java Community Process (JCP) experts groups. He contributed to the servlet and JSP specifications even before formal JCP expert groups existed, and received special mentions for his contributions to the JSP 2.0, JSP Standard Tag Libraries (JSTL) and the JavaServer Faces (JSF) specifications. Hans also helped get the development of the open source Apache Tomcat web container (used as a base for the servlet and JSP reference implementation) started as one of the initial members of the Apache Jakarta Project Management Committee (PMC).
- JavaServer Pages
- JavaServer Pages Pocket Reference
- JavaServer Faces
- Enterprise Java Best Practices (Contributor)
In addition to his books, Hans is also a frequent writer of Java articles for web sites and magazines and an occasional speaker at Java events.
Hans has more than twenty years experience as a software developer and project manager, designing and implementing systems for everything from IBM mainframes, through DEC minicomputers, Unix workstation and servers, to PCs, using many different programming languages. He first came in contact with Object Oriented concepts through Simula in 1985, and has continued to explore this powerful technology in many projects since then using Smalltalk, C/C++ and Java. He developed his first database applications even before SQL was the standard database language, and has worked with network based applications since the late eighties. His experience with Java goes back to 1995, when the language was first made public.
In 1997, Hans founded Gefion Software, a privately held company located in Hermosa Beach, California. Gefion Software is one of the pioneers in the server-side Java field and develops products that simplify development of network based, platform independent applications.