I have been running pivot for nearly a month now, and I am very happy with it. It is a great piece of software, it works like a charm, and is very solid.
Very seldom have I seen such a well-designed piece of open source software. This is a great product with a very professional look and feel and some great features that make using it easy. I hope they add support for multiple blogs and plugins in the future.
An open, cross-platform journaling program.
A scientific plotting package.