Protégé is a free and open-source ontology editor and framework for Linux, Windows and MacOS. Using this application you can create and edit one or more ontologies in a single workspace. It comes with very customizable user interface, interactive navigation, ontology merging, moving axioms between ontologies, rename of multiple entities and more.
Install Protégé on Ubuntu Linux
Protégé is available as a flatpak package file from the flathub repository. So first you need to install flatpak and flathub on your system and restart it after the installation.
Now open the terminal application using the ctrl+alt+t keys and run below Protégé flatpak install command.
flatpak install flathub edu.stanford.protege
It will install the latest version of Protégé on your Ubuntu system. After the installation you can open it using below command.
flatpak run edu.stanford.protege
And uninstall Protégé using below command.
sudo flatpak uninstall edu.stanford.protege