In this paper we present the Alpino Dependency Treebank and the tools that we have developed to facilitate the annotation process. Annotation typically starts with parsing a sentence with the Alpino parser, a wide coverage parser of Dutch text. The number of parses that is generated is reduced through interactive lexical analysis and constituent marking. A tool for on line addition of lexical information facilitates the parsing of sentences with unknown words. The selection of the best parse is done efficiently with the parse selection tool. At this moment, the Alpino Dependency Treebank consists of about 6,000 sentences of newspaper text that are annotated with dependency trees. The corpus can be used for linguistic exploration as well as for training and evaluation purposes.