twodue

Two Due is a powerful To Do List manager with many special features. It supports multiple lists, recurring To Do items, integration with your Web browser, and multiple category levels for each to do item.

Two Due stores its To Do lists in tab-delimited text files. This makes it easy for Two Due to support multiple lists. In fact, Two Due remembers all the files you have previously opened and makes it easy for you to switch between them, remembering and restoring different selection criteria and sort fields for each different file. You can also import data from an external file, adding its items to the currently open list.