EssentialPIM - EssentialPIM is a free Personal Information Manager that keeps up with the times and lets you manage appointments, tasks, notes, contacts, password entries and email messages across multiple devices and cloud applications.

My Personal Kanban - This is a one page HTML/JavaScript application for people who would like to use simple and basic...

Todo.txt - Track your tasks and projects in a plain text file, todo.txt. A todo.

TaskBoard - A Kanban-inspired app for keeping track of things that need to get done.

Task Coach - Task Coach is a simple open source todo manager to keep track of personal tasks and todo lists.

buckets.co - Feature rich kanban board collaboration platform.