SWOOP

Swoop is a nice and smooth application for browsing and editing OWL ontologies. It comes with some of the basic features found in any browser application, together with many other features. It sports a clean and intuitive interface, with some tools at hand.

Intuitive and clean graphical interface

The application doesn't take long to install, but you will need to unzip the files before launching the .bat installation file. It doesn't actually install on your device, which is quite nice, it simply runs the executable file.
The graphical interface is really clean and intuitive, packed with some of the features that you might find in a regular browser. There's the option to adjust some settings to make them meet your preferences.

Search within various ontologies

You have the option to load ontologies or search for them online. Simply type in the URL in the address bar to find information. You can even search for editable ontologies or show inherited files.
It displays class and property trees in a side menu inside the application, simply click on one to get details. The view mode can be changed, pick from two types of sources, RDF/XML or abstract syntaxes.

Check out bookmarks and advanced settings

It comes with some bookmarks that you can check out, shortcuts to various ontologies on the Internet but some of them don't really work. Still, you have the option to add new bookmarks to the list.
Moreover, you can add information in ontologies and lookup certain keywords so you would find details faster. It comes with some other options, like the feature to automatically partition classes or extract modules.
The settings menu offers quite a few tools, change font size and style, display entities using certain labels or automatically save files created inside the application.
All in all, SWOOP is a very nice application for browsing through various ontologies and editing them in various ways.