Joplin - Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, tagged and modified either from the applications directly or from your own text editor.

MUIbase - MUIbase is a relational, programmable database with graphical user interface for Windows, Mac...

OneNote - Get the OneNote app for free on your tablet, phone, and computer, so you can capture your ideas and to-do lists in one place wherever you are. Or try OneNote with Office for free.

My Visual Database - Using My Visual Database, you can create databases for invoicing, inventory, CRM, or any specific purpose.

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

PortaBase - PortaBase (portable database) is a program for conveniently managing one-table database files.