chrony is a client and server for the Network Time Protocol (NTP). This program keeps your computer's clock accurate. It was specially designed to support systems with intermittent Internet connections, but it also works well in permanently connected environments. It can also use hardware reference clocks, the system real-time clock, or manual input as time references.
gnokii is a multisystem tool suite for mobile phones. It provides a library to communicate with a phone hiding the communication protocol. The library handles SMS, phonebook, calendar, phone calls, and other mobile phone capabilities. It supports Nokia-FBUS mobiles, AT-capable phones (most of the mobiles), as well as Symbian-based phones.
The GNU Gatekeeper is a free H.323 gatekeeper based on the OpenH323 project. You can use it to manage a Voice-over-IP network and let endpoints (e.g., Netmeeting) communicate through symbolic names. It also has an external interface for billing and other applications. It runs on a number of Unix versions (including Linux and Solaris) and Windows.
RT is an industrial-grade trouble ticketing system. It lets a group of people intelligently and efficiently manage requests submitted by a community of users. RT is used by systems administrators, customer support staffs, NOCs, developers, and even marketing departments to track issues, outages, bugs, requests, and all kinds of other things at thousands of sites around the world.
keychain helps you to manage ssh keys in a convenient and secure manner. It acts as a frontend to ssh-agent and gpg-agent, but allows you to easily have one long running ssh-agent process per system, rather than the norm of one ssh-agent per login session. This dramatically reduces the number of times you need to enter your passphrase. With keychain, you only need to enter a passphrase once every time your local machine is rebooted. keychain also makes it easy for remote cron jobs to securely "hook in" to a long running ssh-agent process, allowing your scripts to take advantage of key-based logins.
Dar is a shell command that makes backup of a directory tree and files. Its features include splitting archives over several files, DVD, CD, ZIP, or floppies, compression, full or differential backups, strong encryption, proper saving and restoration of hard links, extended attributes, file forks, Door inodes, and sparse files, remote backup using pipes and external commands (such as ssh), and rearrangement of the "slices" of an existing archive. It can run commands between slices, before and after saving some defined files or directories (for a proper database backup, for example), and quickly retrieve individual files from differential and full backups. Several external GUIs exist as alternatives to its CLI interface, like kdar, DarGUI, SaraB, etc.
Ziproxy is a high-performance forwarding (non-caching) HTTP proxy that gzips text and HTML files, and reduces the size of images by converting them to lower quality JPEGs or JPEG 2000. It is intended to increase the speed for low-speed Internet connections (mobile, dial-up, other). It's suitable for both home and professional usage. Ziproxy is fully configurable and also features transparent proxy mode, HTML/JS/CSS optimization, operation in daemon mode, a detailed access log with compression statistics, basic authentication, and more.
SecureSkat is a peer-to-peer implementation of the German card game Skat. The program negotiates participating players and game sessions over an arbitrary IRC network (Internet Relay Chat). Neither a trusted third-party (dealer) nor a centralized game server is necessary. All critical operations, e.g. shuffle of the deck, are performed using advanced cryptographic techniques (so-called Mental Poker solutions) provided by LibTMCG. The outdated OpenSkat branch contains a graphical user interface based on XSkat 3.4. This interface can be used with most recent versions, but must be built separately.