Pxax P2Do(64) is a small, free and extremely useful todo program with its intuitive category and tag system. You are free to use it and introduce it to your friends and family freely. P2do is continuously developed. It features portable (it can run on a USB), category system, category's tags system, calendar with month view, auto zoom into tasks on calendar, add, edit, delete, and search tasks, duedate in friendly style, mark tasks with icons and priority, keyboard shortcuts, intuitive grid layout, small footprint, simple and fast, and built on powerful dotnet framework.
Windows Server 2008,