3 Free and Open-source Diagram Apps for macOS (Intel and Apple Silicon)

1- Dia

Design flowcharts, UML diagrams and Databases

Dia is a free open-source program for designing and building technical diagrams. It is fairly easy to use and can be installed on macOS, Windows, and Linux.

Read about Dia 's features, license, platforms, and more.

2- Nebo

Take smarter, more beautiful notes

Nebo is a free open-source software for note-taking that offers a dozen of productivity-oriented features. It supports handwritten notes, sketches, diagrams and exports your notes in many formats.

Nebo is designed for touch screens, but it also designed to work with stylus and to write or sketch notes.

One of its other stunning features is it also works as a PDF viewer, and you can easily add PDF files to your notebook, create and export your note and annotations easily.

You can also change the background colors, and enjoy the infinite drawing canvas in a free-form page document.

It is important to note that the app is not free, but it is affordable for Windows, Android, and Apple devices.

However, if you prefer using the keyboard, Nebo got you covered easily with dozens of shortcuts, and keyboard specific tools.

The primary reason why we listed it here, is that it does not have an open-source counterpart (alternative) and it was recommended by some medical students.

The app is built for project managers, students, teachers, engineers, designers, writers, and software engineers. However, if you have a stream of ideas, we highly recommend it.

Read about Nebo 's features, license, platforms, and more.

3- Pencil

An open-source GUI prototyping tool that's available for ALL platforms.

Pencil is built for the purpose of providing a free and open-source GUI prototyping tool that people can easily install and use to create mockups in popular desktop platforms.

Read about Pencil 's features, license, platforms, and more.