SubnetMapper is an admin's quick tool to map and keep track of managed IP networks, track free ranges that are available for assigning, and document the network setup. It has been designed to help admins manage and document small to medium networks. It prints and displays freely colorable maps of your network.
AlmostVPN is an SSH tunnel manager with a twist. It is packaged as a Preference Panel, so you do not have to use yet another application to configure your tunnels. Instead, it uses creative network configuration techniques to provide almost VPN-like access to remote services, so you can keep using real IP addresses and port numbers while accessing service on the other side of your tunnels. It provides a simple way to mount remote volumes, use remote printers and faxes, access iTunes, iPhoto, and almost any other Bonjour-based application, transfer and execute files, and more.
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).