An operational forecasting tool for the European region based on continuous monitoring of the ionosphere is available on the World Wide Web for interactive use (http://www.rcru.rl.ac.uk/iono/maps.htm). A network of 23 ground-based vertical incidence ionosondes provides the basic inputs for the region of interest (10/spl deg/W-90/spl deg/E, 30/spl deg/-70/spl deg/N). Measurements of foF2 and M(3000)F2 are sent by e-mail, mainly in the form of URSIGRAM messages as described in ITU-R Recommendation P.313. Data are currently updated every 24 hours, though not all ionosondes provide values over the week-ends. Forecasts and archive measurement maps of the critical frequency foF2 and the maximum usable frequency for a 3000 km range, MUF(3000)F2, are then produced for the area of interest. Comparisons between the maps derived from measured and forecast values have been conducted.