Programs
ihull, a C program which generates the integer hull of a rational polyhedron. It needs no libraries, and it definitely compiles on linux. It would almost certainly compile on OSX, and you could probably get it to work on windows. It implements the algorithm described in "Theory of Linear and Integer Programming" by Alexander Schrijver, especially as explained in these course notes by Rekha Thomas at UW. ihull uses lrslib and Normaliz.
Trans, an example cryptogram decoder program written for Math 2b (probability and statistics), which demonstrates using Bayes' rule to score potential decrypts of a cryptogram (and try to find the best one). The hill-climbing could be better.
CWtoSimp, a script which takes a 2 dimensional CW complex as input and outputs a (homeomorphic) simplicial complex. This can be handy for using Sage to check homology, etc.
Caltech Sage Server
The caltech math department has a Sage server. Click here to learn about it.Summer Seminar 2009
The summer grad student seminar page can be found here.