Managing knowledge (especially tacit knowledge) in small and medium sized enterprises has always been a challenge. They have special characteristics that are related to their size, structure and their mem-bers' coordination and collaboration. Theses specifications affect the process of knowledge management in such enterprises. In addition, they suffer from the missing of codified and standardized supports. All these factors illustrate the urgent need to provide them with an appropriate knowledge management solution. In this paper, the special needs for knowledge management in this kind of enterprises is illustrated. The importance of an effective note-taking tool is justified. A semantic model that takes into account these needs is presented. In addition, we explain our choice of MEMORAe web platform as a tool for knowledge organization. We also clarify the functionalities which have been added to MEMORAe platform in order to be dedicated to these enterprises. Finally, the web platform is introduced.