Voidoria is Fractal Flame rendering and animation software.
libnabo is a fast K Nearest Neighbor library for low-dimensional spaces. It provides a clean, legacy-free, scalar-type–agnostic API thanks to C++ templates.
Kolourmatica is a simple color space calculator that allows conversions between 22 different color spaces. It also renders each color space in every other system color space.
An easy to use, but still quite capable firewall for Netfilter/iptables.
A graphical editor for ISO images.