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 second subsets of data, each tree structure having hierarchically and sequentially arranged nodes representing the corresponding subset of data; aligning the 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 tree structures; and outputting an indication of the parallel textual segments.