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

Simple Calendar - A simple calendar with events (optional recurring and reminders), week numbers and a customizable...

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

Calendar Lock PEA - Calendar Lock PEA is an encrypted desktop calendar with a day, week and month view. The shown calendars are never stored unencrypted on your disk, but exist only in the RAM. Platform-independent, Open Source, no installation or registration required.

CherryTree - A hierarchical note taking application, featuring rich text and syntax highlighting, storing data in a single xml or sqlite file.

MirrorBackup.net - Mirror Backup protects from data loss by continuously monitoring files and folders, and backing them up to the cloud or a local drive when they change.