Disasters are deadly and destructive events, particularly in developing countries, where there is an immediate need to improve natural disaster management capacity, especially at the local level where hazard vulnerability can most effectively be reduced. Since disasters and vulnerability vary spatially, all phases of the disaster management cycle can be improved through the effective use of geospatial information technology (GIT). However, developing countries face many barriers to GIT implementation, and solutions that take these barriers into consideration are required. In general, developing countries lag behind in terms of technology use, and highly technical solutions are not practical to acquire, use and maintain by the local level disaster management practitioner community. This thesis proposes that free and open source software (FOSS) offers a feasible technical solution, and explores the significance of recent developments in this software domain from a GIT and natural disaster management perspective. Specifically, FOSS-based GIT can provide a core set of functionality for the development of critical framework spatial datasets required for the subsequent use of GIT during all phases of the natural disaster management cycle. Using gvSIG, a mature and user-friendly FOSS-based geographic information system, this thesis demonstrates how local level capacity in developing countries can be improved to ultimately reduce natural hazard vulnerability and disaster impacts.