We present three applications which share some of their linguistic processor. The first application "FILES" - Fully Integrated Linguistic Environment for Syntactic and Functional Annotation - is a fully integrated linguistic environment for syntactic and functional annotation of corpora currently being used for the Italian Treebank. The second application is a shallow parser - the same used in FILES - which has been endowed with a feedback module in order to inform students about their grammatical mistakes, if any, in German. Finally an LFG-based multilingual parser simulating parsing strategies with ambiguous sentences. We shall present the three applications in that sequence.