1. A method of identifying parallel bilingual corpora from one or more larger corpora accessible over a network, comprising: selecting a first subset of data in a first language and a second subset of data in a second language; obtaining a tree structure corresponding to each of the first and the second subsets of data, each tree structure having hierarchically and sequentially arranged nodes representing the corresponding subset of data; utilizing a computer processor that is a part of a computer to preprocess the tree structures to form preprocessed tree structures that correspond to the first and the second subsets of data, the preprocessed tree structures having a reduced number of nodes that are formed by deleting and combining at least a portion of the hierarchically and sequentially arranged nodes; aligning the preprocessed tree structures corresponding to each of the subsets of data according to a hierarchically and sequentially invariant alignment; identifying parallel textual segments of the subsets of data based on the alignment of the preprocessed tree structures; and outputting an indication of the parallel textual segments.