I just learned about this software from my mathematician son, and I think it looks like a pretty nice, well-developed system for symbolic math: http://en.wikipedia.org/wiki/Sage_(mathematics_software) It's using Python and is GPL. But when I try to install it, I run into trouble. Any ideas about this?: I'm using the code here for Ubuntu PPA: http://www.sagemath.org/download-linux.html Install Sage this way: apt-add-repository -y ppa:aims/sagemath apt-get update apt-get install sagemath-upstream-binary I ran those three lines, always preceded with "sudo", but the output from that last line was this: E: Package 'sagemath-upstream-binary' has no installation candidate Any ideas? Maybe I need to contact the Sage team about that. Mike