1. A semantic tagging method that outputs semantically linked tags for text content comprising: inputting the text content to a computer; by the computer, extracting nouns and noun phrases from the text content; by the computer, mapping the extracted nouns and noun phrases to terms of an ontology; by the computer, mapping the extracted nouns and noun phrases to a correct sense of the ontology terms using lexical chaining Word Sense Disambiguation (WSD) algorithms; by the computer, weighting the extracted nouns' and noun phrases' concepts from their ontological and statistical features; by the computer, extracting key-phrases from the weighted concepts; and by the computer, outputting the key-phrases as semantic tags; wherein mapping the extracted nouns and noun phrases to terms of an ontology further comprises: accessing the ontology; comparing the nouns and noun phrases with the ontology terms; and if there is an exact match, retrieving the ontology term, and if there is not an exact match, performing phrase mapping using a rule based algorithm; and wherein the phrase mapping rule based algorithm further comprises: generating two sub phrases by removing the first and last word from the noun phrases and replacing the original noun phrases with the two sub phrases; and repeating the phrase mapping until there is a match or there are no more noun phrases remaining.