| Abstract | This research is one of the first few to investigate the acceptance of open source software (OSS) in the context of developing countries, in this case Thailand. It is also the first study to propose a comprehensive model that integrates individual, social, and software characteristics to measure the acceptance of OSS. Based on the three-pronged approach, the study puts forward an integrated model consisting of the extended technology model (TAM2), the innovation diffusion theory (IDT), and software characteristics. A full-scale field survey of 1,005 OSS users was undertaken and both convergent and discriminant validities were conducted. The results of the structural equation modeling (SEM) illustrate that perceived ease of use, perceived usefulness, intention to use, output quality, compatibility, software functionality, and software maintainability have a statistically positive relationship with OSS acceptance. Contrary to most studies, which did not find a positive relationship between visibility and trialability towards the acceptance of OSS, it is interesting to observe that this study did find a positive relationship. This study makes both academic and practical contributions. Not only does this study validate previous findings on technology acceptance, but it also introduces three new constructs, which are software maintainability, software reliability, and software functionality to technology acceptance research. These constructs have not been tested for technology acceptance prior to this study, especially in the context of OSS in a developing country. Although, studies on technology acceptance using TAM and IDT have been undertaken in the past in developing countries, this study is unique in the context that it focuses on OSS acceptance among Thai users. Moreover, this study can also be used as a prototype for other developing countries looking to measure technology acceptance rates in their respective countries. In terms of practical contributions, this study offers some guidelines to the government and to software developers. It provides the Thai government with empirical analysis that will be vital in nurturing the use and acceptance of OSS. The government needs to continue to implement strategies and policies that support the growth of OSS, as this study shows that users are willing to try out and accept OSS if it is made available to them. However, this study also found that users do not perceive OSS to be relevant to their jobs. Therefore, the government should involve the private sector and small and medium enterprises by allocating tax break incentives for them if they use OSS. This will help to attract more users and increase the acceptance rate among Thai users so that they become less dependent on foreign-owned software providers. By taking these measures, the private sector and the government can gradually convince users that not only is OSS cheaper, but it is also better for them. A competitive strategy for OSS to compete with proprietary software must be undertaken to sustain OSS usage in the long run. In order to attract more users, software developers need to understand that OSS must be both useful and compatible, and that OSS users demand the highest output quality. Software authors need to understand that acceptance of OSS also depends on how well the functionality of the software matches the users’ needs. Therefore software developers must develop functions that users will find easy to use, which are also maintainable. |