The Electronic Lab Notebook (ELN) Matrix has been created to aid Harvard researchers in the Longwood Medical Area (LMA) in the process of identifying practical ELN tools to meet their specific research needs. Using the ELN Matrix, researchers can compare and contrast the numerous tools available today, and also explore individual options in-depth. The tools listed in the ELN Matrix are selected strictly on their relevance to the LMA biomedical research community with respect to their intended function to replace and enhance conventional (hard copy) laboratory notebooks.