18. A computer system, comprising: a database, storing a first collection of texts in a first language, and a second collection of texts, which are not parallel to said first collection of texts, that are in a second language; a training processor, that processes said texts to determine portions in the first collection of texts whose meaning is substantially the same as portions within the second collection of texts, by comparing a plurality of sentences within the collection of texts, and determining at least one parameter indicative of a first portion within the first collection and a second portion within the second collection, and using said at least one parameter to determine portions which have similar meanings; and a translation processor, using training data based on said portions which have similar meanings to translate input text between said first and second languages.
18. A computer system, comprising: a database, storing a first collection of texts in a first language, and a second collection of texts, which are not parallel to said first collection of texts, that are in a second language; a training processor, that processes said texts to determine portions in the first collection of texts whose meaning is substantially the same as portions within the second collection of texts, by comparing a plurality of sentences within the collection of texts, and determining at least one parameter indicative of a first portion within the first collection and a second portion within the second collection, and using said at least one parameter to determine portions which have similar meanings; and a translation processor, using training data based on said portions which have similar meanings to translate input text between said first and second languages. 19. The system recited in claim 18 , wherein said training processor iteratively operates, by training a dictionary, and then comparing again said first collection and said second collection.