Open source software is becoming a credible and realistic alternative to proprietary software in municipalities. The aim of this thesis is to explore the strategies and logical issues that inspire and motivate municipalities to migrate into or integrate use of open source software. The research approach used in the study is an explorative, comparative case study performed in the three Swedish municipalities of Falköping, Alingsås and Kungälv, which considers implementation and use of OpenOffice in administration. The methodologies used in the case study were in-depth interviews with Chief Information Officers in the municipalities and document analysis. The interviews were combined with the tool of SWOTanalysis to further focus on the reasons for choosing OpenOffice as an application program. There is certainly not a unique strategy to migrate into or integrate use of Free/Open Source Software. Since each municipality is autonomous in the process of decision-making, various strategic planning or guidelines are use in different municipalities. In the municipalities of Alingsås and Kungälv the strategic planning is used for leading the processes of implementation of new software applications. However, in Falköping municipality, the procedures are guided by a set of guidelines. The lower Total Cost of Ownership and the Free/Open Source Software’s freedoms besides many other advantages, make the municipalities stimulated to migrate into use of OpenOffice suite. In contrast, there are some drawbacks and barriers, such as shortage of internal and external standardization and lack of user knowledge and familiarity, which demotivate the municipalities to take this decision. To lower costs of IT administration seems to be the most significant factor in motivating municipalities to migrate into use of OpenOffice. More research is needed in order to find out the consequences of implementation of OpenOffice in municipalities as well as to investigate if Total Cost of Ownership really is decreased by the use of Open Office.