erpcd-talker is a simple set of utilities which communicate with an erpcd (used by Xylogics or Bay Annex terminal servers) to verify a username and password and get an IP address. It can be easily integrated into a ppp daemon or used in a fake ftp daemon which can in turn be validated against by some Macintosh login control software.
Domtools is a set of Unix shell commands that allow you to traverse DNS domain hierarchies, list all hosts (or subdomains) within a given domain, convert a host name to an IP address and vice-versa, convert a normal IP address to "in-addr.arpa." format and vice-versa, and more. These commands can be used manually, or included as building blocks for higher level DNS tools. Output is easily computer parsable.
Digicam is a simple and easy-to-use command-line utility to take, retrieve, and delete pictures from a Kodak DC21x camera. While the code is based on gphoto kodak_dc21x library, it fixes many annoying bug fixes in gphoto implementation, and allows for more options. Since digicam requires no user interaction and takes all the parameters from command line, it can be used in webcam-like scripts and for automatic image capture.