Protégé is described as 'Free, open source ontology editor and knowledge-base framework' and is an app in the office & productivity category. There are eight alternatives to Protégé for a variety of platforms, including Windows, Web-based, Mac, iPad and Linux apps. The best Protégé alternative is TheBrain, which is free. Other great apps like Protégé are Visual Understanding Environment, Fluent Editor, Onto4ALL and CmapTools.
TheBrain helps you organize all your Web pages, contacts, documents, emails and files in a context-driven visual map.
United States
Visual Understanding Environment (VUE) is a mind-mapping and concept-mapping tool. It is also a non-linear presentation program.
United States
An ontology editor focused on providing a seamless experience for users working with OWL ontologies. It supports the editing of structured ontologies and offers various validation and reasoning tools.
Poland
EU
Onto4ALL Is a free graphical editor capable of creating, editing and exporting ontologies being guided by an warnings console, an ontological building rules tab and an extensive palette of ontological classes and relationships.
Brazil
concept maps on servers, edit their maps synchronously (at the same time) with other users on the Internet, and search the web for information relevant to a concept map.
3D Topicscape is a Personal Information Manager that provides a template loosely based on mind-mapping or concept mapping. It presents the mind map as a 3D scene where each node is a cone (or pyramid, or variation on such a shape). It can also display in a 2D format.
United Kingdom
Unilexicon™ a visual editor and taxonomy manager for authoring controlled vocabularies with a content tagging extension.
