Unless otherwise indicated, all the software listed is free!
Serif Software Virtually all of my wordprocessing, desktop publishing, image manipulation, panoramas and drawings are carried out on various Serif programs. This link takes you to free Starter Editions of many of their titles.
Irfanview Image Viewer Argueably the best free image viewer and converter around. Can use Photoshop plugins, create slideshows and screen savers. A must-have.
Virtualdub A completely free, but flexible, powerful and easy to use video editor.
Audacity For a free audio editor and recorder, look no further.
DVDFlick Author DVDs complete with menus and burn straight to DVD.
PhotoLapse Converts a list of jpeg images to an avi movie.
FFMPEG A video conversion library with staggering capability. It is command-line driven and so is also staggeringly user-unfriendly. Fortunately there is FFE, a flexible, user-friendly graphical front end to FFMPEG.
Fractint Despite its great age and still running on DOS this is probably the best fractal generating program around.
Apophysis A non-Mandelbrot fractal generator.