PHD2 is the enhanced, second generation version of the popular PHD guiding software from Stark Labs. Still available free of charge, PHD is now an open-source project, supported by an active community of developers and astro-imagers.
Download v2.6.3 for Mac OS XDownload v2.6.3 for Windows
Bruce Waddington has contributed a new PHD2 dithering application. This handy utility can be used to dither PHD2 from applications like MaxIm that do not have built-in support for PHD dithering. Download: PHD_Dither 1b