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.
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.
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.
Suricata is an Intrusion Detection and Prevention (IDS/IPS) engine developed by the Open Information Security Foundation and its supporting vendors. The engine is multi-threaded and has native IPv6 support, file extraction capabilities, and many more features. It's capable of loading existing Snort rules and signatures, and supports many frontends through Barnyard2.
PDFtk Server is a simple commandline tool for doing everyday things with PDF documents. You can use it to merge PDF documents or collate PDF page scans, split PDF pages into a new document, rotate PDF documents or pages, decrypt input as necessary (password required), encrypt output as desired, fill PDF forms with X/FDF data and/or flatten forms, generate FDF data stencils from PDF forms, apply a background watermark or a foreground stamp, report PDF metrics, bookmarks, and metadata, add/update PDF bookmarks or metadata, attach files to PDF pages or the PDF document, unpack PDF attachments, burst a PDF document into single pages, uncompress and re-compress page streams, and repair corrupted PDF files (where possible).
Flowgrind is a tool similar to iperf or netperf. It measures throughput and other metrics for TCP and other protocols. It features some unique characteristics: a distributed architecture, sophisticated flow scheduling, Linux kernel TCP statistics, the Anderson-Darling statistical test, rate-limited flows with uniform or Poisson distribution, and separation between control and test traffic.