The COLUMBIA UNIVERSITY
COMPUTER MUSIC CENTER
The MULTIMEDIA INSTITUTE, Zagreb
The CROATIAN ACADEMIC
Partner company which helped system maintenance
sgi freeware is a project of SiliconGraphics Inc, one of world's leading supercomputer manufacturers, who have been also known as one of the pioneers in the Open Source movement, to port and optimize hundreds of Open Source programs to the 64-bit high-end UNIX operating system IRIX®.
UNIX is probably the longest living and most vital of all operating systems. It is known for its power, stability, reliability, networking and flexibility. It originates in a research project at Bell Laboratories in the seventies, upon completion od the project the system was released. Several UNIX based systems exist in the world these yeare, both commercial (IRIX, MacOSX, UNICOS, AIX, HPUX) and free (LINUX, SOLARIS, FreeBSD). Even though they run on completely different hardware, they all have in common that programs written for UNIX are source-compatible. Many UNIX programs are free, and are being distributed in source-code format. Essential part of all UNIX systems are compilers (programs which translate the source code into the machine-executable format, such as excellent and free GNU gcc). Therefore UNIX systems are especially interesting to the academic community. Another educative point in UNIX is that the system does not try to "hide" things from the user, as compareed to some office-oriented OS, which makes it very "fair" and transparent, but also obliges the user to know more than casual browsing. More about UNIX can be read from here.
GNU (Gnu is Not Unix): global project for creation, licensing and protection of free UNIX compatible software, founded by Richard Stallman in 1984, when interests of rivaling commercial enterprises threatend to tear apart and forever destroy the spirit, legacy, openness and freedom of original UNIX. Thanks to GNU and the Free Software Foundation it is surviving. Thanks to GNU, there are thousands of free enterprise strength programs available. Without GNU, it's a question if UNIX, as we know it today would exist at all? Even most commercial UNIX systems so heavilly rely on GNU software, that they would be hardly thinkable without it.
LINUX is probably the most wide-spread and popular UNIX like operating system. It started as a comletely open research project of Finnish software engineer Linus Torvalds, to make a entirely free UNIX compatible operating system for Intel-based computers. Today it also works on PowerPC processors (Apple and IBM). Because it is free and open, and is beeing permanently improved, educational systems in some of world's leading countries (such as USA, China, France), chose it for primary operating system in the universities.
OpenGL is the world standard in 2D and 3D visualization, copyrighted by SiliconGraphics, Inc. On application programming level it is a set of C-language commands, which formalize the science of descriptive geometry, lighting, texture, scenes, etc. Even though the technology is not OpenSource (one can argue there would also not be much sense, because it mostly deals with graphic hardware and low-level drivers), it is open in terms of being integrated into all graphic cards which support the OpenGL specification, and is therefore platform independent and free. It works on almost all operating systems, and many of OpenGL libraries are both free and OpenSource, such as libglx. However, there is also a completely OpenSource alternative to OpenGL, the MESA 3D libraries.
X is the network-transparent graphic user interface standard for all UNIX systems. Even though some UNIX based systems (such as MacOSX) don't install it as default, one can get it through XFree86 organization. X is interesting because it is free, and because all free UNIX program which use graphic interface use X.