According to a study by the European Commission, the total value of Open Source Software (OSS) in 2006 was 12 billion euros. The market share of OSS is expected to rise to 32 percent by 2010. As a result, many significant companies and organizations have already made or are preparing for a software transition. The acceptance of OSS by employees is a crucial success factor in this process. The author Robert Csato demonstrates in this practical study, taking into account the systematic and structured approach of the DART model, how typical acceptance barriers and groups can be identified. Additionally, based on the analysis results, general, specific, and group-specific measures to increase the acceptance of OSS are presented. Furthermore, strategies to avoid resistance to OSS during the transition phase are developed. Thus, the book represents a valuable contribution for organizational leaders and software developers for the efficient implementation of OSS on employee desktops.