eXo Platform - Digital workplace solution

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

ifttt - IFTTT puts the internet to work for you. Create simple connections between the products you use every day.

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

Apache Airflow - Airflow is a platform to programmaticaly author, schedule and monitor data pipelines.

Strikethru - Strikethru is a kind of to-do list notebook for managing work lists and staying updated with the important tasks.