Okular is a universal document viewer application for Windows as well as Linux. This is the only application you need to open and view documents of many different formats. It supports document formats such as PDF, PS, ODT, EPub, DJVU and MD. It supports image file formats such as JPEG, PNG, GIF, Tiff and, WebP. It supports comic book and magazine formats like CBZ and CBR. It can also open CHM help files for you on non-Windows platforms.
Okular is particularly very suitable for reading comic books (CBZ or CBR) and magazine files on large screen computers. It has a unique user interface in which we can use the drag-n-drop method to open any file. For all the files, it shows the thumbnails on the sidebar. In the case of CBR, CBZ or PDF files, a list of thumbnails for all the pages is shown. We can jump to any of these pages simply by selecting them from this list.
Okular makes for easy reading by allowing so many different viewing modes. It can be switched to the fullscreen mode. We can make it automatically fit the pages to the screen, fit pages by their width or fit pages by their length.
Okular might not support the audio files as such but it can read out the text documents using the OCR technology. It can read out the currently opened document in its entirety or you can make it read out aloud only a single page.
Okular can be configured to use less or more system resources. For example, we can turn off transparency effects to reduce the CPU usage. Similarly, we can make it use less RAM by turning off the preloading of the next pages in advance. However, turning off these features is only needed on very old systems.
You can download Okular from https://okular.kde.org/.