Stellarium - Planetarium software.
DIYPhotobits.com Camera Control - Shutter control software for exposures up to 30s, does not work in BULB-mode.
Deepskystacker - Stacking software for deepsky images.
Registax - Stacking software for planetary images.
GradientXterminator - With this Photoshop plug-in you can remove amplifier glow and vignetting and balance the background color in one click!
PHD guiding - Software for autoguiding and periodic error (PE) measurement.