The Societe Francaise d'Anesthesie et de Reanimation have provided an extremely useful online severity-of-illness calculator, for critically ill and preoperative patients. The site presents about 40 scoring systems in two groups, adult and pediatric, which are subdivided into general and specialized scores. This provides access to a comprehensive directory of severity-of-illness scoring systems, including critical care, trauma, preoperative, and nursing intervention evaluations. It is easy to use, with dropdown lists limiting the requirement for text entry. Useful 'help' links or appendices describe all relevant definitions needed to generate an accurate score. Laboratory values are provided in both SI and non-SI units, making the calculators usable internationally. Each scoring system is appropriately referenced, and relevant formulae are shown. This feature helps the user to gain insight into the methodology of the score generated. Each scoring system has its own URL, facilitating book-marking. The pages are very easy to navigate, and the author's name is identified at the bottom of each page with an e-mail link. Although the authors state that this resource is only a calculator, an overview of severity-of-illness scoring systems would add value. A brief introduction refers to a paper by Lemeshow and Legall, and a French-language review is provided. The addition of a brief outline of the role, advantages, and disadvantages of each scoring system would add further value. In some aspects the layout could be improved, such as the dropdown lists. Nevertheless, this is a very useful web resource for the intensive care clinician or researcher, and is a valuable aid that facilitates utilization of the more complex scoring systems.