Research

OpenBSD is a Unix-like computer operating system descended from Berkeley Software Distribution (BSD), a Unix derivative developed at the University of California, Berkeley. It was forked from NetBSD by project leader Theo de Raadt in late 1995. The project is widely known for the developers' insistence on open source code and quality documentation, uncompromising position on software licensing, and focus on security and code correctness. The project is coordinated from de Raadt's home in Calgary, Alberta, Canada. Its logo and mascot is a pufferfish named Puffy.

Tru64 UNIX is a 64-bit UNIX operating system for the Alpha instruction set architecture (ISA), currently owned by Hewlett-Packard (HP). Previously, Tru64 UNIX was a product of Compaq, and before that, Digital Equipment Corporation (DEC), where it was known as Digital UNIX (formerly DEC OSF/1 AXP).

Spring was an experimental microkernel-based object oriented operating system developed at Sun Microsystems in the early 1990s. Using technology substantially similar to concepts developed in the Mach kernel, Spring concentrated on providing a richer programming environment supporting multiple inheritance and other features. Spring was also more cleanly separated from the operating systems it would host, divorcing it from its Unix roots and even allowing several OSes to be run at the same time. Development faded out in the mid-1990s, but several ideas and some code from the project was later re-used in the Java programming language libraries and the Solaris operating system.

Slackware is a free and open source Linux-based operating system. It was one of the earliest operating systems to be built on top of the Linux kernel and is the oldest currently being maintained.[1] Slackware was created by Patrick Volkerding of Slackware Linux, Inc. in 1993. The current stable version is 13.37, released on April 27, 2011.

Windows NT 3.1 is the first release of Microsoft's Windows NT line of server and business desktop operating systems, and was released to manufacturing on 27 July 1993. The version number was chosen to match the one of Windows 3.1, the then-latest operating environment from Microsoft, on account of the similar visual appearance of the user interface. Two editions of NT 3.1 were made available, Windows NT 3.1 and Windows NT Advanced Server. It was succeeded by Windows NT 3.5 in September 1994.

Newton OS was the operating system for the Apple Newton PDAs produced by Apple from 1993-1997. Newton OS was written entirely in C++ and trimmed to be low power consuming and use the available memory efficiently. Similar to the original Apple Macintosh, many applications were written in the ROM of the Newton to save DRAM and flash space for user applications.

NetBSD is a freely available open source version of the Unix-derivative Berkeley Software Distribution (BSD) computer operating system. It was the second open source BSD descendant to be formally released, after 386BSD, and continues to be actively developed. The NetBSD project is primarily focused on high quality design, stability and performance of the system. Due to convenient license and portability, NetBSD is often used in embedded systems.

FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX,” as the direct descendant of BSD UNIX (many of whose original developers became FreeBSD developers), FreeBSD’s internals and system APIs are UNIX-compliant, and thanks to its permissive licensing terms, much of FreeBSD’s code base has become an integral part of other operating systems such as Mac OS X that have subsequently been certified as UNIX-compliant and have formally received UNIX branding. With the exception of the proprietary Mac OS X, FreeBSD is the most widely used BSD-derived operating system in terms of number of installed computers, and is the most widely used freely licensed, open-source BSD distribution, accounting for more than three quarters of all installed systems running free, open-source BSD derivatives.

Plan 9 from Bell Labs is a distributed operating system. It was developed primarily for the research purposes as the successor to Unix by the Computing Sciences Research Center at Bell Labs between the mid-1980s and 2002. Plan 9 is most notable for representing all system interfaces, including those required for networking and the user-interface, through the filesystem rather than specialized interfaces. Plan 9 aims to provide users with a workstation-independent working environment through the use of the 9P protocols. Plan 9 continues to be used and developed in some circles as a research operating system and by hobbyists.

Solaris is a Unix operating system originally developed by Sun Microsystems. It superseded their earlier SunOS in 1993. Oracle Solaris, as it is now known, has been owned by Oracle Corporation since Oracle's acquisition of Sun in January 2010.