Dolphin is a file manager that lets you navigate and browse the contents of your hard drives, USB sticks, SD cards, and more. Creating, moving, or deleting files and folders is simple and fast.
Ark is a graphical file compression and decompression utility with support for multiple formats, including tar, gzip, bzip2, rar and zip, as well as CD-ROM images. Ark can be used to browse, extract, create, and modify archives.
Okular is a universal document viewer that combines the excellent functionalities with the versatility of supporting different kind of documents, like PDF, Postscript, DjVu, CHM, XPS, ePub and others.