No area in the study of human languages has a longer history and a higher practical signifi cance than lexicography. The advent of the computer has dramaticually changed this discipline in ways which go far beyond the digitisation of materials in combination with effi cient search tools, or the transfer of an existing dictionary onto the computer. They allow the stepwise elaboration of what is called here Digital Lexical Systems, i.e., computerized systems in which the underlying data - in form of an extendable corpus - and description of lexical properties on various levels can be effi ciently combined. This paper discusses the range of these possibilities and describes the present form of the German „Digital Lexical System of the Academy“, a project of the Berlin-Brandenburg Academy of Sciences (www.dwds.de).