Stack Exchange is a network of question-and-answer websites on topics in varied fields, each site covering a specific topic, where questions, answers, and users are subject to a reputation award process. The sites are modeled after Stack Overflow, a Q&A site for computer programming questions that was the original site in this network. The reputation system allows the sites to be self-moderating. User contributions are licensed under Creative Commons Attribution-ShareAlike 3.0 Unported. In 2008, Jeff Atwood and Joel Spolsky created Stack Overflow, a question-and-answer Web site for computer programming questions, which they described as an alternative to the programmer forum Experts-Exchange. In 2009, they started additional sites based on the Stack Overflow model: Server Fault for questions related to system administration and Super User for questions from computer "power users". In September 2009, Spolskys company, Fog Creek Software, released a beta version of the Stack Exchange 1.0 platform as a way for third parties to create their own communities based on the software behind Stack Overflow, with monthly fees. This white label service was not successful, with few customers and slowly growing communities.