Technology is rapidly changing the speed and manner in which people interact with each other and with the world. As technology helps criminals to operate more easily and quickly across borders, so law enforcement capability must continuously improve to keep one step ahead. Computer forensics has become a specialized and accepted investigative technique with its own tools and legal precedents that validate the discipline. Specially designed forensic software is also widely used during the whole process of computer forensic investigation. This article introduces computer forensic and computer evidence, introduces and compares some forensic software, and summarizes its likely future development.