JlinAlg is a an easy-to-use Java-library for linear algebra. I discovered this project when I needed a Java-based linear algebra packet that can handle fractions. As things you don't pay for are never good enough (payed things will never be good enough ither), I decided to chip in and did a fair bit of additions, refactoring, debugging, added factories, generics (Java 5) and probably zillions of more bugs. Join in and help find them ;-)