muCommander is a cross-platform file manager with a dual-pane interface that features support for FTP, SFTP, SMB, NFS, HTTP, Amazon S3, Hadoop HDFS, Bonjour/Zeroconf, email attachments, archives in many formats (including Zip, RAR, 7z, GZip, Tar, Bzip2, ISO, NRG, AR, Deb, and LST), bookmarks, credential management, themes, multiple windows, full keyboard control, and many configuration options. It is available in 23 languages.
Duplicate Files Searcher is an application for finding and deleting duplicate files on your computer. It can also be used to calculate MD5 and SHA hashes. It has features such as manual files selection (giving the user full control over files to be deleted), byte for byte file comparison, file preview, several file comparison methods, and more.
Phuzby will let you search your organisation's LDAP directory (such as Active Diretory, Novell eDirectory, or OpenLDAP) for the contact details of colleagues, customers, or suppliers. Phuzby can display a photo for each person, and can even read the telephone number out loud to help you dial it correctly. In fact, if your phone system supports TDMF tones, you can hold your handset near you PC's speaker and phuzby will dial the number for you.
GNUstep is a cross-platform, object oriented environment composed of frameworks, tools, and servers (daemons). It is very similar to the Cocoa frameworks from Apple, and tries to maintain compatibility with Cocoa wherever it is desired and possible. The frameworks provide classes for containers, distributed objects, object archiving, file management, text system, font management, image composition, WYSIWYG PostScript graphics, and more.