Ghostscript is a processor for PostScript and PDF files. It can rasterize these files to a wide variety of printers, devices for screen preview, and image file formats. Since applications tend to prepare pages for printing in a high-level format such as PostScript, most Unix users with low-level bitmap printers, such as inkjets, use GhostScript as part of the printing process. In addition, Ghostscript is capable of converting PostScript files, functionality comparable to Adobe Acrobat Distiller, but on the command line. In addition, Ghostscript is used for file import and viewing by a great many other applications, including xv, ImageMagick, gimp, and xdvi. Several GUI wrappers for viewing PostScript and PDF files exist, including GSview, ghostview, gv, ggv, and kghostview. This is far from a comprehensive list.
db4o is an object database for Java and all .NET environments. Its features include ACID transactions, automatic class schema recognition, query-by-example, a S.O.D.A. object querying API, native queries, LINQ support on .NET, callback methods, memory files, cascade-on-delete, multi-threaded access, and Java Webstart and servlet support.
Cfengine is a tool for setting up and maintaining BSD and System-5-like operating system optionally attached to a TCP/IP network. You can think of cfengine as a very high level language, much higher level than Perl or shell: a single statement can result in many hundreds of operations being performed on multiple hosts. Cfengine is good at performing a lot of common system administration tasks, and allows you to build on its strengths with your own scripts.
GNU Make examines the timestamps on a set of interdependent files, and, if necessary, issues commands to bring them up-to-date. The user creates a makefile describing the files, their relationships, and the commands to run. Most often make is used to rebuild libraries and programs when their sources are changed, but it can be used for any situation where one set of files needs to be generated from another set.
pdnsd is a Proxy DNS server for Linux and FreeBSD that is designed to cope with unreacheable nameservers (e.g. because the dial-in link is not up) in a graceful manner to prevent DNS-dependent applications like Netscape from hanging. It has a permanent disk cache (i.e. the cache contents are saved in a file on exit) and supports parallel query and a wide variety of link uptests. It also has the ability to serve some types of locally defined records.
XBoard is a graphical chessboard for X that can serve as a user interface to play against any of a variety of chess engines that run on your local machine, or against human or computer opponents on an Internet chess server. XBoard can also be used by itself to read and write game files in PGN (portable game notation). WinBoard is a port of XBoard to Microsoft Win32.
PostGIS adds support for geographic objects to the PostgreSQL object-relational database. In effect, PostGIS "spatially enables" the PostgreSQL server, allowing it to be used as a backend spatial database for geographic information systems (GIS), much like ESRI's SDE or Oracle's Spatial extension.
Ora2Pg is a Perl module to export an Oracle database schema to a PostgreSQL compatible schema. It connects your Oracle database, extracts its structure, and generates an SQL script that you can load into your PostgreSQL database. It dumps the database schema (tables, views, sequences, indexes, grants) with primary, unique, and foreign keys into PostgreSQL syntax without editing the SQL code generated. It also dump Oracle data into PostgreSQL DB as online process or into a file. You can choose what columns can be exported for each table.
muCommander is a cross-platform file manager with a dual-pane interface that features support for FTP, SFTP, SMB, NFS, HTTP, Amazon S3, Hadoop HDFS, Bonjour/Zeroconf, email attachments, archives in many formats (including Zip, RAR, 7z, GZip, Tar, Bzip2, ISO, NRG, AR, Deb, and LST), bookmarks, credential management, themes, multiple windows, full keyboard control, and many configuration options. It is available in 23 languages.