Datomic
MySQL
MarkLogic Server
Valentina Server
Firestore
Datahike
Matisse
Oracle TimesTen
EssentialPIM
Task Coach
Todo.txt
Todoist
CherryTree
GTDNext
Strikethru
DropTask
Datomic
EssentialPIMEssentialPIM is recommended for individuals, freelancers, and small businesses seeking a centralized and efficient tool for managing various types of information. It is especially beneficial for those who prefer an all-in-one application to keep track of meetings, tasks, contacts, and emails without needing multiple separate apps.
MySQL - The world's most popular open source database
Task Coach - Task Coach is a simple open source todo manager to keep track of personal tasks and todo lists.
MarkLogic Server - MarkLogic Server is a multi-model database that has both NoSQL and trusted enterprise data management capabilities.
Todo.txt - Track your tasks and projects in a plain text file, todo.txt. A todo.
Valentina Server - Valentina Server is 3 in 1: Valentina DB Server / SQLite Server / Report Server
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.