Due to continuous progress in information technology and the rise of a knowledge-based economy, almost all companies actively build information systems to support outreach and quickly respond to the competitive environment of a fast-changing world. However, free software is now a popular trend in the software-application industry. The industry gathers public knowledge to achieve openness and a lower cost, the acquisition of which is gradually changed from pure community discussion to commercial activity. Due to strong support and promotion by the government, free software has become a solution for small businesses because of the price issue. What is the influence of free software on an enterprise? How does a small business actually adopt free software to build their information systems? Does free software actually reduce costs and also upgrade competitive ability? How far can a small business adopt free software? In this study we want to evaluate these kinds of problems. We desire to help small businesses make decisions on decisions on building information systems with free software and reach their objectives through those applications which use information technology effectively.