It shouldn't be necessary in Linux since there is a filesystem notification system (inotify) that sends file and directory change notification events to applications (including the GNOME and KDE file managers and desktops). OS X has a similar facility (FSEvents) that works with Finder. In fact, Windows has a similar facility as well, but, for some reason, Windows Explorer (which does actually seem to use it) doesn't always pick up on the notification events. I don't know enough about the underlying implementation to understand why that is so, but strictly speaking, the refresh item should hypothetically be irrelevant on Windows as well. Unfortunately, it is still sometimes necessary for some reason.
Ocular is a complete PDF Viewer with several features and a built-in annotation system, including several types of marking. The reader itself is also an excellent PDF Viewer with a lot of customizations. The Reader itself is really a small, fast, and lightweight software. Ocular also features a lot of features that you do not find in free PDF readers. For instance, it does not support all the formatting such as the use of tables, bullet lists, etc. This software can be used for PDF document viewing in the office or the web. It supports all popular formats, such as PDF, PUB, RTF, and plain text, and even can create your own file types as well. You can preview your PDF files, make notes about them, mark up and annotate them, and more! Ocular uses the very powerful Java technology, allowing you to easily manipulate the documents, create, access,.