Based on our record, AllegroGraph seems to be more popular. It has been mentiond 1 time since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
However, Protege is a modeling tool not a database. So when you start getting into large amounts of data (e.g., 10K instances or more) you will need another tool, ideally a database. There are tools to do what's called Data Virtualization, where you can represent your data (what OWL users call the A-Box, i.e., the equivalent of instances in OOP or rows in a relational DB) in a relational database and map the data... Source: almost 2 years ago
Dia - Dia is a GTK+ based diagram creation program for GNU/Linux, MacOS X, Unix, and Windows, and is released under the GPL license.
neo4j - Meet Neo4j: The graph database platform powering today's mission-critical enterprise applications, including artificial intelligence, fraud detection and recommendations.
draw.io - Online diagramming application
ArangoDB - A distributed open-source database with a flexible data model for documents, graphs, and key-values.
yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.
OrientDB - OrientDB - The World's First Distributed Multi-Model NoSQL Database with a Graph Database Engine.