The project included many technology contributions among Linux, Solaris and SPARC. The Afara CPU used a SPARC port of Debian Linux initially. Debian Linux contributions to Afara Websystem’s former CPU architecture continued to grow, including commercial support for Ubuntu, a Debian-based Linux operating system. Afara Websystems’ former platform direction seemed further validated when Sun hired Ian Murdock, founder of the Debian distribution, to head operating system platform strategy, and cross-pollinate Solaris with a new OS packaging technology similar to that of Debian Linux.

The new CPU architecture of Afara Websystems, which became known as “Niagara”, had enough merit to cause a competing internal Sun project under DeSantis’ organization, called “Honeybee”, to be canceled.

Pressure was placed on the computing industry to add cores and threads. While competing microprocessor vendors were designing dual-core chips with two dual-threads per core, the original “Niagara” architecture was a more radical design: an eight core processor with four threads per core.

The new family of SPARC microprocessors, trademarked by Sun as “CoolThreads”, was released with model names of UltraSPARC T1 (in 2005), UltraSPARC T2 (in 2007), and UltraSPARC T2 Plus (in 2008). While SPARC is an open instruction set architecture, where vendors build their own processors to an open specification defined by SPARC International, this new family of microprocessors was not only created to the open specification, but its implementation was now free, where people could download the source code, and manufacture them independently.

For web serving loads, Sun had catapulted to become the uncontested fastest single processor on the planet in December 2005, performing 7x faster than the closest Intel server, and has been consistently the highest throughput web server, with the closest competition being 2x-3x slower (socket to socket comparison) as of mid-2009.

Olokotun returned to Stanford University to head its “Pervasive Parallelism Lab” in 2008, to help shape the future of software, as he did with hardware.

Adapted from the Wikipedia article Afara Websystems, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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SCO Skunkware, often referred to as simply “Skunkware”, is a collection of Open Source software projects ported, compiled, and packaged for free redistribution on SCO operating environments. SCO Skunkware packaged components exist for SCO Xenix, SCO UNIX, SCO OpenServer 5, SCO OpenServer 6, UnixWare 2, Caldera OpenLinux, Open UNIX 8, and UnixWare 7. SCO Skunkware was an early pioneering effort to bring open source software into the realm of business computing and, as such, provided an important initial impetus to the acceptance and adoption of open source software in the small and medium business market. An extensive SCO Skunkware download area has been maintained since 1993 and SCO Skunkware components were shipped with operating system distributions as far back as 1983 when Xenix for the IBM XT was released by The Santa Cruz Operation. Later additional open source distributions for operating platforms such as the FreeBSD Ports collection and the Solaris Freeware repository would lend additional momemtum to the adoption of open source in the business community.

Adapted from the Wikipedia article SCO Skunkware, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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GRUB is dynamically configurable. It loads its configuration at startup, allowing boot-time changes such as selecting different kernels or initial RAM disks. To this end, GRUB provides a simple, bash-like, command line interface which lets users write new boot sequences.

GRUB is highly portable. It supports multiple executable formats, and is geometry translation independent. Although Multiboot compliant, GRUB supports non-multiboot operating systems such as Microsoft Windows and OS/2 via chain loading. GRUB supports all commonly used Unix file systems, VFAT and NTFS used by Windows, as well as Logical Block Address (LBA) mode. GRUB allows users to view the contents of files on any supported file system.

GRUB can be used with a variety of different user interfaces. Most Linux distributions take advantage of GRUB’s support for a graphical interface to provide a customized boot menu with a background image, and occasionally mouse support. GRUB’s text interface can be set to use a serial link to provide a remote terminal boot loader access.

GRUB can download operating system images from a network, and thus can support diskless systems. GRUB supports automatic decompression of OS images prior to booting from them.

GRUB differs from other boot loaders by being able to communicate with a user directly via a GRUB command prompt. A GRUB prompt is the stage before GRUB loads an operating system and can be triggered at a text-mode GRUB booting screen (which is controlled by the configuration file “menu.lst” (or “grub.cfg”: see below)) by pressing the “c” key. A command prompt can also be obtained by booting GRUB without an operating system attached, or in a GRUB installation with an operating system where the file “menu.lst” is absent. From there, a user can manually select and control booting from any installed operating system by using console commands. To boot an operating system automatically, the appropriate commands are placed in a configuration file named “menu.lst” in a designated subdirectory.

GRUB has a rich set of terminal commands that allow a user at the GRUB prompt to view the hard disk partition details, alter partition settings, temporarily re-map the disk order, boot any user-defined configuration file and view the configuration of other boot loaders in file formats GRUB supports. Thus, without prior knowledge of what is installed on a computer, one can use GRUB from an external device such as a floppy disk, USB device or a CD-ROM to boot up an installed operating system.

GRUB uses a scrollable screen for operating system boot selection. This means 150 or more boot choices can be easily controlled by GRUB by adding them to the “menu.lst” configuration file. The arrow keys are used to select which operating system to boot.

One boot loader can run another boot loader by ”chainloading”. GRUB uses the same two to three lines of command sequences to boot any DOS, Windows, Linux, BSD or Solaris system, making it very easy to work with.

Although GNU GRUB can be pre-packaged or retro-built into Unix-like operating systems, there are also specific GRUB implementations for DOS and Windows. GRUB can also be installed stand alone, unattached to any operating system. Its implementation requires one file for booting from a CD and two files for booting from a floppy, hard disk or USB device. These files are available from any Linux Live CD that supports GRUB, making it easily and freely obtainable.

Adapted from the Wikipedia article GNU GRUB, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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Cygwin consists of a library that implements the POSIX system call API in terms of Win32 system calls, a GNU development toolchain (such as GCC and GDB) to allow software development, and a large number of application programs equivalent to those on the Unix system. Many Unix programs have been ported to Cygwin, including the X Window System, KDE, GNOME, Apache, and TeX. Cygwin permits installing inetd, syslogd, sshd, Apache, and other daemons as standard Windows services, allowing Microsoft Windows systems to emulate Unix and Linux servers.

Cygwin programs are installed by running Cygwin’s “setup” program, which downloads the necessary program and feature package files from repositories on the Internet. Setup can install, update, and remove programs and their source code packages. A full installation may take up to 4 GB of hard disk space.

Efforts to reconcile concepts that differ between Unix and Windows systems include:

*A Cygwin-specific version of the Unix mount command allows Windows paths to be mounted as “filesystems” in the Unix file space. Mount information is normally stored in the registry. Filesystems can be mounted as binary ones (by default), or as text-based ones, which enables automatic conversion between LF and CRLF endings (this only affects programs that call open or fopen without specifying text or binary. Programs installed by Cygwin’s setup program always open files in binary mode when appropriate, thus avoiding the problem). Disk drives (C:, D:, etc.) are also denominated /cygdrive/c, /cygdrive/d, etc. Windows network paths of the form \HOSTSHAREFILE are mapped to //HOST/SHARE/FILE.

*Full-featured ”/dev” and ”/proc” file systems are provided. ”/proc/registry” provides direct filesystem access to the registry.

*Symbolic links are provided, and use .LNK files (Windows shortcuts) containing Cygwin-specific information, and with the “system” attribute set to speed up processing. However, native NTFS symbolic links are handled differently; using the rm command deletes the linked file instead of the link itself. Old Cygwin versions handled symbolic links using plain text files with hidden attribute set and a single line of text, pointing to the destination file or directory.

*The Solaris API for handling access control lists (ACLs) is supported and maps to the Windows NT ACL system.

*Special formats of /etc/passwd and /etc/group are provided that include pointers to the Windows equivalent SIDs (in the GECOS field), allowing for mapping between Unix and Windows users and groups.

*Various utilities are provided for converting between Windows and Unix file formats, for handling line ending (CRLF/LF) issues, for displaying the DLLs that an executable is linked with, etc.

*The Cygwin library also interfaces to existing Windows libraries. It is possible to call Windows functions like waveOut from Cygwin executable itself.

The version of gcc that comes with Cygwin has various extensions for creating Windows DLLs, specifying whether a program is a windowing or console mode program, adding resources, etc. It also provides support for compiling MinGW-compatible executables (that is, executables that do not require Cygwin to be installed to run, or more specifically, executables that don’t require Cygwin’s CYGWIN1.DLL, which provides the POSIX compatibility layer).

Cygwin is used heavily for porting many popular pieces of software to the Windows platform. It is used to compile Sun Java, OpenOffice.org, and even server software, like lighttpd.

Red Hat normally licenses the Cygwin library under the GNU General Public License version 2 with an exception to allow linking to any free and open source software whose license conforms to the Open Source Definition. Red Hat also sells commercial licenses to those who wish to redistribute programs that use the Cygwin library under proprietary terms.

Adapted from the Wikipedia article Cygwin, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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PCBoard supported the 16C550 UARTS (universal asynchronous receiver transmitter), such as 16550 UART (“Fifo”), 16554 UART and 16650 UART, which made it possible to run multiple nodes of the BBS on a single (multitasking) computer using either using IBM OS/2 or the DOS multitasking tool DESQview in combination with the memory manager QEMM. Some sysops tried to run PCBoard on the (then) new Windows 95 operating system by Microsoft

] and reported mixed results with it. Stability was critical for a BBS, which was usually running 24/7 and the early version of the Microsoft 32bit operating system was not. Windows 95 was never officially supported by CDC.

Standard PCs then and today have only one or two (if any) serial ports (COM ports), which are needed to connect an external modem to a computer. This made multiport cards like the G-Tek “BlackBoard”, “BBS550″ or “SmartCard” and the “DigiCard” by Digi International popular among sysops. Other options were internal multi-modem cards and multiple computers connected by local area network.

PCBoard also supports ISDN (Integrated Services Digital Network) and Telnet access via the Internet. The open source communications terminal program SyncTERM, available for Win32, Linux, FreeBSD, NetBSD, OpenBSD, Solaris and Mac OS X can be used for example to connect to the few remaining PCBoard BBS installations that are connected to the Internet.

Adapted from the Wikipedia article PCBoard, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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BALL (Biochemical Algorithms Library) is an extensive open source C++ framework of algorithms and data structures for molecular modelling and computational structural bioinformatics. The library also offers a Python scripting interface. Among the supported systems are Linux, Solaris, Microsoft Windows, and MacOS X. The library is supplemented with command-line utilities and supports display with Qt and OpenGL as well.

There is a molecular viewer BALLView developed by the same team, which allows viewing and editing several other molecular file formats, e.g., PDB, HIN, MOL2 and many more. It is the visulization component of BALL. Both BALL and BALLView are available under LGPL and GPL licences. The programs are developed and maintained by the groups of Hans-Peter Lenhof, Oliver Kohlbacher and Andreas Hildebrandt. BALLView is an application written in C++ that uses BALL for molecular modeling and visualizing molecular models. It is available under the GPL license for Linux, Windows, and Mac OS.

Adapted from the Wikipedia article BALL, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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Intel x86 supports 4MB pages (called Page Size Extension) (2MB pages if using PAE) in addition to its standard 4kB pages, and other architectures may often have similar features. IA-64 supports as many as eight different page sizes, from 4kB up to 256MB. This support for ”huge pages” (known as ”superpages” in FreeBSD, and ”large pages” in Microsoft Windows terminology) allows for “the best of both worlds”, reducing the pressure on the TLB cache (sometimes increasing speed by as much as 15%, depending on the application and the allocation size) for large allocations while still keeping memory usage at a reasonable level for small allocations.

Huge pages, despite being implemented in most contemporary personal computers, are not in common use except in large servers and computational clusters. Commonly, their use requires elevated privileges, cooperation from the application making the large allocation (usually setting a flag to ask the operating system for huge pages), or manual administrator configuration; operating systems commonly, sometimes by design, cannot page them out to disk.

Linux has supported huge pages on several architectures since the 2.6 series via the hugetlbfs filesystem. Windows Server 2003 (SP1 and newer), Windows Vista and Windows Server 2008 support huge pages under the name of ”large” pages. Windows 2000 and Windows XP support large pages internally, but are not exposed to applications. Solaris beginning with version 9 supports large pages on SPARC and x86.

FreeBSD 7.2-RELEASE features superpages. Note that in Linux, applications need to be modified in order to use huge pages. On FreeBSD and Solaris, applications take advantage of huge pages automatically, without the need for modification.

Newer AMD64 processors can use 1GB pages in long mode, as well as Intel’s Westmere processors.

Adapted from the Wikipedia article Page (computer memory), under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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MMDF, the Multichannel Memorandum Distribution Facility, is a mail transfer agent (MTA), a computer program designed to transmit e-mail. It was originally developed at the University of Delaware in the late 1970s, and provided the initial means of operating CSNet, the predecessor to NSFnet. It grew in popularity throughout the 1980s, and was selected by The Santa Cruz Operation as the MTA it would distribute with SCO UNIX in 1989. It was also adopted as the basis for other commercial efforts, including the gateway used to connect the MCI Mail service to Internet mail. A re-coded variant of MMDF, called ”Pascal MDF” (PMDF) was written at the University of Pennsylvania for VMS and was eventually commercialized through Innosoft, which subsequently ported PMDF to Tru64 Unix and Solaris. In 1999 PMDF was translated from Pascal to C. The C version of PMDF became the basis of Sun’s Java Messaging System, while rights to PMDF itself were

purchased by Process Software, which then ported PMDF to Linux.

Adapted from the Wikipedia article MMDF, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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Although Sun was also interested in supporting multiple operating systems, their needs were nowhere as pressing as IBM or Apple. By this point in time they had already moved platforms from their early 68k-based machines to their SPARC-based lineup, and their UNIX System V-based Solaris operating system was taking over from their BSD-based SunOS. Sun’s concerns were somewhat more subtle: keeping developers interested in Sun’s version of Unix; and, allowing their system to scale downwards onto smaller devices such as set-top boxes. A microkernel-based system would be particularly useful in this latter role.

Spring concentrated on “programmability”; making the system easier to develop on. The primary addition in this respect was the development of a rich interface definition language (IDL), which exported interfaces with considerably more information than the one used in Mach. In addition to functions and their parameters, Spring’s interfaces also included information about what errors can be raised and the ”namespace” they belong to. Given a proper language, programs, including operating system servers, could import multiple interfaces and combine them as if they were objects native to that language — notably C++. Some time later the Spring IDL was adopted with minor changes as the CORBA IDL.

Spring also explored a number of specific software advances in file systems, virtual memory and IPC performance. The result was a single Unix-like system with much better performance than Mach. Some of these changes are detailed below.

Adapted from the Wikipedia article Spring (operating system), under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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Supported (guessable) filesystem or partition types:

* BeOS filesystem type.

* FreeBSD/NetBSD/386BSD disklabel sub-partitioning scheme used on Intel platforms.

* IBM OS/2 High Performance filesystem.

* Linux ext2 (second extended filesystem).

* Linux LVM physical volumes (LVM by Heinz Mauelshagen).

* Linux swap partitions (versions 0 and 1).

* The Minix operating system filesystem type.

* MS-DOS FAT12/16/32 “filesystems”.

* MS Windows NT/2000 filesystem.

* The Reiser filesystem (version 3.5.X, X > 11).

* Silicon Graphics’ journalling filesystem for Linux.

* Sun Solaris on Intel platforms uses a sub-partitioning scheme on PC hard disks similar to the BSD disklabels.

* Other types may be added relatively easily, as separately compiled modules.

* QNX 4.x filesystem.

Adapted from the Wikipedia article Gpart, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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