Philip Greenspun is a semi-retired computer scientist and educator. According to the website, Greenspun is the author of several computer science textbooks, including the Internet Application Workbook and a concise SQL tutorial. Because of the obvious connection between his books and the Internet, he is also an Internet entrepreneur, but only an early one. However, his identity is not only that just mentioned, but he is also a pilot, Greenspun holds an airline transport pilot certificate. So, he also works as a commercial pilot in Delta Air Lines subsidiary Comair and teaches others how to pilot aircraft. I learned about Greenspun's two most famous points from its website. The first was to release the software behind photo.net in a community system called Arsdigita as a free open-source toolkit. Eventually, based on the biography on the site, I discovered that the software had grown into a $20 million open-source company. That's what the biography says: “The software is best known for its support of public online communities, such as www.scorecard.org and photo.net, which grew to serve 500,000 users educating each other to become better photographers.” I think this is probably the early BBS, where everyone can discuss and communicate with various people and solve their difficulties. There is no doubt that this is a very positive thing. The second thing is Greenspun is an early developer of database-backed websites which has become the primary approach to user-contributed engineering websites. “Greenspun was a developer of one of the first Web-based electronic medical record systems. Greenspun's Oracle-based community site LUSENET was an important early host of free forums. In 1995, Greenspun was hired to lead the development of Hearst Corporation's Internet services, which included some early e-commerce sites.” To quote Philip Greenspun himself: “I'm good at things that most people are bad at and bad at things that most people are good at.”