Imagemagick

Remind is a sophisticated calendar and alarm program. It includes the following features: - A sophisticated scripting language and intelligent handling of exceptions and holidays. - Plain-text, PDF, PostScript and HTML output. - Timed reminders and pop-up alarms. - A friendly graphical front-end for people who don't want to learn the scripting language. - Facilities for both the Gregorian and Hebrew calendars. - Support for 12 different languages.

Open-source native PDF reader for Windows.

Open-source screenshot and OCR utility.

Open-source colour and palette utility.