The core concept of Free Open Source Software (FOSS) is that full access to software source code must be granted in order to give individuals the freedom to create, use and distribute software. It emphasises the logic of non-discrimination to create conditions for free action and thought. This makes FOSS to be reminiscent of the Ujamaa policy of Tanzania which argues for all members of the society to have equal rights and equal opportunities. This thesis presents a theoretical and empirical informed analysis of FOSS development in information systems (IS) using cases from the health and education sectors in Tanzania. It focuses on the interplay between the socio-technical conditions of IS in developing countries and the FOSS development approach. The research design was based on participatory action research. The objectives were to illuminate the design-reality gaps in FOSS development in the context of developing countries. Three archetypal situations that exacerbate the reality of FOSS implementation in developing countries were identified as developer – sponsor, global developer – local developer, and local developer – local user gaps. The thesis recommends that, implementing FOSS in IS requires substantial investment on localising the software, training users, and developing support networks. The advantage of FOSS development in developing countries centres on the formation of sustainable collaborative networks through sharing of software and knowledge. These networks are important in helping a developing country to support the day to day customisation and managing of FOSS products. Based on the findings of this study, an alternative conceptualisation of FOSS development which emphasises co-located project organisations as a coping strategy to meet the challenges of social-technical influences is advisable. This is a different approach from working on virtual teams as the literature presents the development and organisation approaches of FOSS.