Open Source Software is a term used to identify software developed and released under an “open source” license, meaning that under certain conditions; it is openly available for use, inspection, modification, and for redistribution free of cost (or with cost based on the license agreement). Incorporation of OSS while developing software can reduce time and cost of development. The nature of the work force (volunteers and paid) in OSS projects is transient and results in high turnover leading to knowledge loss. In this work, we explore the phenomenon of knowledge loss in OSS projects. Maintenance of OSS projects requires knowledge, typically shared asynchronously using technology-mediated channels. Knowledge sought in this manner is reactive in the sense that a developer will consult these channels looking for possible solutions or supporting information. We follow the backward snowballing to study the relevant literature on knowledge loss in OSS. Our work suggests that proactive knowledge exchange mechanisms may bring some benefits to OSS projects. Further integration of knowledge management practices with the established OSS practices can minimise knowledge loss.