In this paper we present several use cases for the Stockholm TreeAligner, a software tool originally designed for annotating the alignments in a parallel treebank. The tool has been extended and improved to the point that it can now also serve as a general tool for browsing and searching monolingual and parallel treebanks. Among the use cases presented are: building a parallel treebank, browsing mono- and bilingual treebanks, consistency checking using the search function, comparing PP-attachment in different languages, and viewing different versions of the same treebank. A demonstration of the software will be held during the workshop.