- sports and mountains
http://www.svkyffhaeuser.de/ sports club "SV Kyffhäuser e.V." (in german) http://www.kyffhaeuser-berglauf.de/ a special mountain run, called "Kyffhäuser-Berglauf" (in german) http://www.dav-muenchen.de/ homepage of the german Alps-association, department Munich (in german) http://www.via-ferrata.de/ information about fixed rope routes (in german) http://www.kraxl.de/ information about mountain hikes (in german) - cryptology and security
http://www.cryptool.com// free program to learn about and use a couple of cryptological methods http://www.gnupg.de/ The GNU Privacy Guard http://www.keyserver.net/ OpenKeyServer http://www.cacr.math.uwaterloo.ca/hac/ handbook of the applied cryptography http://www.schneier.com/blog/ Bruce Schneier's weblog on latest security topics - mathematics
http://pari.math.u-bordeaux.fr/ a free algebra and number theory package http://maxima.sourceforge.net/ a free computer algebra system http://www.research.att.com/~njas/sequences/ the online encyclopedia of integer sequences http://www.genealogy.ams.org/ the mathematics genealogy project http://mathworld.wolfram.com/ Wolfram's Mathworld http://www.mathe-seiten.de/ homepage about mathematics by Thomas Peters (in german) - programming
http://www.haskell.org detailed information about the functional programming language Haskell http://gprolog.inria.fr/ GNU Prolog http://www.javabuch.de/ handbook of JAVA-programming (in german) http://www.ruby-lang.org/en/ Scala - a modern programming language which integrates both functional and object-oriented features - friends
http://www.betschinski.de/ Homepage of Axel Betschinski (in german) http://www.michael-fuchs.net/ Homepage of Michael Fuchs (in german) http://www.martin-markowski.de/ Homepage of Martin "Fasi" Markowski (in german) - miscellaneous
http://www.unibw.de/inf/ University of the federal armed forces, Munich, faculty for Computer Science http://www-en.htw-berlin.de/ University of Applied Sciences, "Hochschule für Technik und Wirtschaft", Berlin http://kant.be.schule.de/ Grammar school "Immanuel Kant", Berlin-Lichtenberg (in german)