The KASKADE 3.1 software package solves linear scalar elliptic and parabolic problems in 1, 2, 3 space dimensions with adaptive finite element methods. Furthermore, the toolbox includes extensions for handling systems of equations and example algorithms for nonlinear methods used in obstacle, porous media or Stefan problems. The core of the program is a variety of multilevel/multigrid preconditioners for the arising linear systems. The code, a programmer's manual describing the software design, and a user's guide are available by anonymous ftp from the MGNet or from the eLib at the Konrad-Zuse-Zentrum in Berlin. elib: ===== ftp elib.zib-berlin.de in the subdirectories /pub/kaskade/3.x and /pub/kaskade/Manuals/3.x