Ceres

Ceres is a program for doing various sound effects in the frequency domain and displaying sonograms. The program has been developed for more than 15 years (probably), and is originally made by Øyvind Hammer. Smaller contributions from Jonathan Lee, Stanko Juzbasic and many others.

Jeremy Salwen has a version in his hub working with gtk2: https://github.com/jeremysalwen/Ceres4