There has been considerable investigation into the nature, effectiveness and performance of virtual organizationsvirtual teams and virtual collaboration based on the affordances of  information and communications technology (ICT). The recent emergence of location-based social network technologies has resulted in new modes of ad hoc virtual organizations. Developers appear to improvise systems by cobbling together existing applications and technologies, almost overnight, with uncoordinated contributions rather than traditional designs or project plans. Heylighen theorizes that stigmergic self-organization explains this kind of system development. As defined by the biologist Grassestigmergy has been defined as a sequence of indirect stimulus and response behaviors that contribute to the coordination of actions among insects through their environment, for example termites coordinating their nest building activities. Heylighen likens human cognitive self-organization to stigmergy. In recent years, the advent of distributed ICTs like worldwide internet computing and pervasive ubiquitous networks have made traditional top-down techniques of system development increasingly irrelevant for software application  development. Instead, modular, adaptable and self-managing end-user components are combined in mash-ups. Similarly, software development teams are spontaneous and ad hoc, functioning as virtual organizations. In this study, the actions leading to the creation of the Ushahidi software platform and its subsequent adaptations are identified using longitudinal case study methodology and content analysis methods applied to newspaper, magazine, website, journal and social networking publications. Based on a socio-technical theoretical framework, the Ushahidi system is framed as a dynamic, ad hoc virtual organization in the context of emergency response. The actions leading to the instantiation of the Ushahidi system are examined as examples of human cognitive stigmergic response to critical incidents and naturalistic development of complex adaptive systems.