This paper documents the many taxometric and cartographic achievements of the Salzburg school of dialectometry. It discusses the following topics: 1) problems of measurement of linguistic atlas data (with particular emphasis on Romance linguistic atlases), 2) establishment of a data matrix, 3) choice of a similarity index (Relative and Weighted Identity Value), 4) generation of the respective similarity and distance matrices, 5) their subsequent cartographic exploitation, which encompasses the following cartographic tools: similarity maps, parameter maps and dendrograms (and their spatial projection). The ultimate purpose of these highly sophisticated cartographic techniques (choropleth and isarithmic maps) is to increase our knowledge of the complex mechanisms of the dialectal management of space by man. From a methodological point of view our paper deals with problems related to Romance dialectology and Romance linguistic geography ("géographie linguistique"), historical linguistics, numerical classification, statistics and statistical cartography. The examples are drawn from the French linguistic atlas ALF (Atlas linguistique de la France) published by Jules Gilliéron and Edmond Edmont (Paris: Champion, 1902-1910, 10 volumes) more than one hundred years ago. The taxometric calculations and their respective visualizations are realized by a powerful computer program called "Visual DialectoMetry" (VDM), created by Edgar Haimerl (Blaustein, Germany) between 1997 and 2000 in Salzburg, which is freely available for research purposes.