Many developing countries currently face common problems regarding Information and Communications Technology (ICT). These problems typically include the lack of technical and know-how knowledge and the lack of appropriate technologies to meet their information processing and software needs. The situation worsens with the absence of adequate investment in technology and clear policies for technology adoption and use. Increasing interest in end users’ reactions to ICT has elevated the importance of theories that predict and explain ICT acceptance and use. This paper seeks to investigate the application of two such theories, the Technology Acceptance Model (TAM), and the Theory of Adoption and Diffusion to FOSS, to the adoption rate of FOSS in the Jamaican Public Sector.