Monday morning, 7 am, a new week starts: On the first day of the new week you decide to install the new compiler gcc 3.1. On the second day, you downloaded and installed the CLN library, version 1.1.5. On the third day you got GiNaC, version 1.0.9. On the fourth day you played around with Root, version 3.03.06. On the fifth day you decided, that you would like to have TeXmacs 1.0.0.9 as editor. Now it's Saturday night, you look back at what you have done this week. You know that all your packages work well, but you are still not satisfied ! You ask for more ! Now it's time to download gTybalt 0.1.0 from http://www.fis.unipr.it/~stefanw/gtybalt.html, which will make all your packages work together. Epilogue: Sunday morning: Some people just relax, others download nestedsums 1.1.0 and calculate loop integrals in quantum field theory with it.