This paper presents a robust client/server implementation of a word sense disambiguator for English. This system associates a word with its meaning in a given context using dictionaries as tagged corpora in order to extract semantic disambiguation rules. Semantic rules are used as input of a semantic application program which encodes a linguistic strategy in order to select the best disambiguation rule for the word to be disambiguated. The semantic disambiguation rule application program is part of the client/server architecture enabling the processing of large corpora.