SIMD-accelerated libjpeg-compatible JPEG codec library
libjpeg-turbo is a JPEG image codec that uses SIMD instructions (MMX, SSE2, NEON, AltiVec) to accelerate baseline JPEG compression and decompression on x86, x86-64, ARM, and PowerPC systems. On such systems, libjpeg-turbo is generally 2-6x as fast as libjpeg, all else being equal. On other types of systems, libjpeg-turbo can still outperform libjpeg by a significant amount, by virtue of its highly-optimized Huffman coding routines. In many cases, the performance of libjpeg-turbo rivals that of proprietary high-speed JPEG codecs. libjpeg-turbo implements both the traditional libjpeg API as well as the less powerful but more straightforward TurboJPEG API. libjpeg-turbo also features colorspace extensions that allow it to compress from/decompress to 32-bit and big-endian pixel buffers (RGBX, XBGR, etc.), as well as a full-featured Java interface.
3D Without Boundaries
VirtualGL redirects 3D commands from a Unix/Linux OpenGL application onto a server-side GPU and converts the rendered 3D images into a video stream with which remote clients can interact to view and control the 3D application in real time.
High-speed, 3D-friendly, TightVNC-compatible remote desktop software
TurboVNC is a high-performance, enterprise-quality version of VNC based on TightVNC, TigerVNC, and X.org. It contains a variant of Tight encoding that is tuned for maximum performance and compression with 3D applications (VirtualGL), video, and other image-intensive workloads. TurboVNC, in combination with VirtualGL, provides a complete solution for remotely displaying 3D applications with interactive performance. TurboVNC's high-speed encoding methods have been adopted by TigerVNC and libvncserver, and TurboVNC is also compatible with any other TightVNC derivative. TurboVNC forked from TightVNC in 2004 and still covers all of the TightVNC 1.3.x features, but TurboVNC contains numerous feature enhancements and bug fixes relative to TightVNC, and it compresses 3D and video workloads much better than TightVNC while using generally only 5-20% of the CPU time of the latter. Using non-default settings, TurboVNC can also be made to compress 2D workloads as "tightly" as TightVNC.
Powerful desktop publishing software
Scribus is an Open Source program that brings professional page layout to Linux, BSD UNIX, Solaris, OpenIndiana, GNU/Hurd, Mac OS X, OS/2 Warp 4, eComStation, and Windows desktops with a combination of press-ready output and new approaches to page design. Underneath a modern and user-friendly interface, Scribus supports professional publishing features, such as color separations, CMYK and spot colors, ICC color management, and versatile PDF creation.
A portable, multi-platform, command-line driven graphing utility
A famous scientific plotting package, features include 2D and 3D plotting, a huge number of output formats, interactive input or script-driven options, and a large set of scripted examples.
A universal instant messaging (IM) program
See https://pidgin.im/about/ for more information. Pidgin is an instant messaging program which lets you log in to accounts on multiple chat networks simultaneously. It runs on Windows, Linux, and other UNIX operating systems. Pidgin is compatible with the following chat networks out of the box: AIM, ICQ, Google Talk, Jabber/XMPP, MSN Messenger, Yahoo!, Bonjour, Gadu-Gadu, IRC, MXit, Novell GroupWise Messenger, Lotus Sametime, SILC, SIMPLE, MySpaceIM, and Zephyr. It is written in C and makes heavy use of GLib and GTK+. Finch is a command line instant messaging program. It also lets you log in to accounts on multiple chat network simultaneously, and it is compatible with the same chat networks as Pidgin. It is written in C and makes heavy use of GLib and ncurses.
An intuitive molecular editor and visualization tool
Avogadro is an advanced molecular editor designed for cross-platform use in computational chemistry, molecular modeling, bioinformatics, materials science and related areas. It offers a flexible rendering framework and a powerful plugin architecture.
Versatile Commodore Emulator
VICE is an emulator collection which emulates the C64, the C64-DTV, the C128, the VIC20, practically all PET models, the PLUS4 and the CBM-II (aka C610). It runs on Unix, MS-DOS, Win32, OS/2, Acorn RISC OS, BeOS, QNX 6.x, Amiga, GP2X or Mac OS X machines.
Hard disk drive and SSD health inspection tool
GSmartControl is a graphical user interface for smartctl. It allows you to inspect the hard disk and solid-state drive SMART data to determine its health, as well as run various tests on it.
Fast C++ library for linear algebra (matrix maths) and scientific computing. Easy to use functions and syntax, deliberately similar to Matlab. Uses template meta-programming techniques. Also provides efficient wrappers for LAPACK, BLAS, ATLAS, ARPACK and SuperLU libraries, including high-performance versions such as OpenBLAS and Intel MKL. Useful for machine learning, pattern recognition, signal processing, bioinformatics, statistics, finance, etc. For more details, see http://arma.sourceforge.net
utility to split mp3, ogg vorbis and FLAC files without decoding
mp3splt is a free utility to split mp3, ogg vorbis and FLAC files without decoding, selecting begin/end time; if file is an album, you can get splitpoints automatically from internet or a local cue, cddb file. It also splits Mp3Wrap and AlbumWrap archives. Supports splitting and trimming by silence detection. For mp3 files, both ID3v1 and ID3v2 are supported using original tags or user defined tags.
Open Source Solid Modeling CAD
BRL-CAD is a powerful cross-platform constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing for rendering & geometric analyses, network distributed framebuffer support, image & signal-processing tools.
3D game engine (more powerful redesign of the Cube engine) and FPS game
CLISP is a portable ANSI Common Lisp implementation and development environment by Bruno Haible. Interpreter, compiler, debugger, CLOS, MOP, FFI, Unicode, sockets, CLX. UI in English, German, French, Spanish, Dutch, Russian, and Danish.
Creates 3D models from photographs
Regard3D is a free, multiplatform, open-source structure-from-motion application. It creates 3D models of objects, based on photographs from different angles.
One hundred command line tools in a small and portable binary.
Create zip files, extract zip files, replace text in files, search in files using expressions, stream text editor, instant command line ftp and http server, send folder via network, copy folder excluding sub folders and files, find duplicate files, run a command on all files of a folder, split and join large files, make md5 checksum lists of files, remove tab characters, convert CR/LF, list newest or biggest files of a folder, compare folders, treesize, show first or last lines of a file, find filenames fast using index files, rename many files using expressions, copy part of a file, change times of a file, set file time from filename, print colored text to terminal, convert csv to tab separated, download files from web, send http or udp requests, print tcp or udp traffic, create hexdump of files, join many text files into one, list nested .zip .tar .tar.gz .tar.bz2 archive contents. Fully portable, for USB stick, without installation. For Windows, Linux and Mac OS/X.
WikidPad is a wiki-like notebook for storing your thoughts, ideas, todo lists, contacts, or anything else you can think of to write down.
Finds problems in MP3 files and helps the user to fix many of them using included tools. Looks at both the audio part (VBR info, quality, normalization) and the tags containing track information (ID3.) Also includes a tag editor and a file renamer.
CAM XML Editor for XML+JSON+Hibernate+SQL Open-XDX sponsored by Oracle
The CAM editor is the leading open source XML Editor/Validation/Schema toolset for rapidly building / deploying XML /JSON /Hibernate /SQL data /Forms applications. Visual WYSIWYG data design, rule entry wizards + drag & drop dictionary components. Will import, analyze / refactor from XML Schema / JSON. Oracle is a proud enterprise sponsor; with NIEM.gov support. Do SQL data import/map+ Open Data API delivery+ Hibernate JPA + UI Forms/Pencil Makes XSD schema (default, flatten, NIEM, & OASIS modes) + JAXB bindings; Mindmap FreeMind or UML models(XMI); XML unit test & live SQL data; HTML docs + spreadsheets (NIEM IEPDs). Canonical component dictionaries from schema sets, SQL, JSON, ERwin XSD, or spreadsheets. The XML CAM templates (OASIS standard) store the exchange structure, content model, code lists, DBMappings, SQL lookups+business rules (XPath). Java CAMV XML/JSON validation engine is a complete exchange test framework [XMLUnit, TEAM(Schematron)]. Java/Eclipse +Saxon/XSL
Artha is a handy thesaurus based on WordNet with distinct features like global hotkey look-up, passive desktop notifications, regular expression based search, etc.. Artha may be used as a free open-source replacement to the proprietary WordWeb Pro.
Console based rcon client for minecraft servers.
Mcrcon is IPv6 compliant minecraft rcon client with bukkit coloring support. It is well suited for remote administration and to be used as part of automated server maintenance scripts. Does not trigger "IO: Broken pipe" or "IO: Connection reset" spam bug on server side. Precompiled binaries available for Windows (x86), Linux (x86) and Mac OS X (x86 / x86-64). Program is written in C99 with getopts options handler (POSIX). It compiles on all proper compilers and environments which supports POSIX and C99 (basically almost all C compiler environments). *Note that this app is still in beta stage so there might be quirks and incomplete implementations of features here and there. No major problems know at the moment.* Project github: https://github.com/Tiiffi/mcrcon
A PDF parsing, modification and creation library.
The PoDoFo library is a free, portable C++ library. It can parse and modify existing PDF files and create new ones from scratch. It also includes several tools to work with PDF files. It features an unique approach which provides access to PDF documents via an object tree. Therefore, PDFs can be created and or manipulated using a simple tree structure.
GemRB is a portable open-source implementation of the Infinity Engine
GemRB (Game engine made with pre-Rendered Background) is a portable open-source implementation of Bioware's Infinity Engine. It was written to support pseudo-3D role playing games based on the Dungeons & Dragons ruleset (Baldur's Gate and Icewind Dale series, Planescape: Torment). It should run on GNU/Linux, Microsoft Windows, OS X, possibly other UNIX derivatives and more. It is licensed under the GPL.
NOT UNDER ACTIVE DEVELOPMENT (sorry)
THIS LIBRARY IS NOT UNDER ACTIVE DEVELOPMENT (sorry). AIMLBot (Program#) is a small, fast, standards-compliant yet easily customizable .NET dll implementation of an AIML (Artificial Intelligence Markup Language) based chatter bot. AIMLBot has been tested on both Microsoft's runtime environment and Mono.
Psycle is a Music tracker (like FastTracker 2 or Impulse Tracker) combined with plugin modularity. It supports its own plugin API, the VST2 plugin standard, and a tracker style sampler playback.