Fugu SSH is a Mac OS X graphical frontend to OpenSSH's Secure File Transfer application (SFTP). SFTP is similar to FTP, but, unlike FTP, the entire session is encrypted, meaning no passwords are sent in cleartext form, and it is thus much less vulnerable to third-party interception. Fugu allows you to take advantage of SFTP's security without having to sacrifice the ease of use found in a GUI. Fugu also includes support for SCP files transfers, and the ability to create secure tunnels through SSH.
iHook is a graphical frontend for any command-line executable. It gives scripts a pleasant Aqua face, and allows script writers to provide graphical feedback without having to learn one of the higher APIs available for Mac OS X. iHook accomplishes this through its ability to understand a set of directives. When a script writes an iHook Directive to stdout, iHook will modify its own interface based on the content of the Directive. In this way, a simple shell script can have an Aqua interface, complete with a progress bar and drawer. When launched in the Finder, iHook prompts the user to choose a script to run; iHook also accepts file drops on its icon, and will attempt to run the dropped file. When no user is logged in, iHook tries to execute /etc/logout.hook. This makes iHook highly useful as an interface for Mac OS X LogoutHooks.
NSFileHandleExt is an Objective-C extension (Cocoa/GNUstep) for the NSFileHandle class (which handles files/sockets). This extension provides support for much easier network programming for protocols like HTTP, IRC, telnet, etc. (everything that sends messages in lines suffixed by \n).
OilCan is a native Universal Binary multithreaded query tool for PostgreSQL. It supports multiple query windows and multiple queries in one window, and includes a basic schema browser. Each query window gets its own connection. All queries run in their own thread, allowing other operations to continue while a long running query is running.