Free software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, not price: users and computer programmers are free to do what they want with their copies of a free software regardless of how much is paid to obtain the program. Computer programs are deemed "free" if they give both programmers and end-users ultimate control over the software and, subsequently, over their devices.
Darwin is an open-source Unix-like operating system first released by Apple Inc. in 2000. It is composed of code developed by Apple, as well as code derived from NeXTSTEP, BSD, Mach, and other free software projects.
A system administrator, or sysadmin, is a person who is responsible for the upkeep, configuration, and reliable operation of computer systems; especially multi-user computers, such as servers. The system administrator seeks to ensure that the uptime, performance, resources, and security of the computers they manage meet the needs of the users, without exceeding a set budget when doing so.
Theo de Raadt is a South African-born software engineer who lives in Calgary, Alberta, Canada. He is the founder and leader of the OpenBSD and OpenSSH projects and was also a founding member of NetBSD. In 2004, De Raadt won the Free Software Award for his work on OpenBSD and OpenSSH.
GNU Screen is a terminal multiplexer, a software application that can be used to multiplex several virtual consoles, allowing a user to access multiple separate login sessions inside a single terminal window, or detach and reattach sessions from a terminal. It is useful for dealing with multiple programs from a command line interface, and for separating programs from the session of the Unix shell that started the program, particularly so a remote process continues running even when the user is disconnected.
pax is an archiving utility created by POSIX, defined since 1995. Rather than sort out the incompatible options that have crept up between tar and cpio, along with their implementations across various versions of Unix, the IEEE designed a new archive utility that could support various archive formats with useful options from both archivers. The pax command is available on Unix and Unix-like operating systems and on IBM i, Microsoft Windows NT, and Windows 2000.
OpenVPN is open-source commercial software that implements virtual private network (VPN) techniques to create secure point-to-point or site-to-site connections in routed or bridged configurations and remote access facilities. It uses a custom security protocol that utilizes SSL/TLS for key exchange. It is capable of traversing network address translators (NATs) and firewalls. It was written by James Yonan and is published under the GNU General Public License Version 2 (GPLv2).
Remote administration refers to any method of controlling a computer from a remote location. Software that allows remote administration is becoming increasingly common and is often used when it is difficult or impractical to be physically near a system in order to use it. A remote location may refer to a computer in the next room or one on the other side of the world. It may also refer to both legal and illegal remote administration.
TrueOS is a discontinued Unix-like, server-oriented operating system built upon the most recent releases of FreeBSD-CURRENT.
DesktopBSD is a Unix-derivative, desktop-oriented operating system based on FreeBSD. Its goal is to combine the stability of FreeBSD with the ease-of-use of K Desktop Environment 3, which is the default graphical user interface.
OS-level virtualization is an operating system paradigm in which the kernel allows the existence of multiple isolated user space instances. Such instances, called containers, Zones, virtual private servers (OpenVZ), partitions, virtual environments (VEs), virtual kernels, or jails, may look like real computers from the point of view of programs running in them. A computer program running on an ordinary operating system can see all resources of that computer. However, programs running inside of a container can only see the container's contents and devices assigned to the container.
Linux Professional Institute (LPI) offers three different certification tracks. The core certification program, Linux Professional, contains three different levels addressing distinct aspects of Linux system administration. The organization also offers an introductory Essentials program for beginners in Linux and open source, as well as an Open Technology track for professionals working with additional technologies such as DevOps and BSD.
A proprietary device driver is a closed-source device driver published only in binary code. In the context of free and open-source software, a closed-source device driver is referred to as a blob or binary blob. The term usually refers to a closed-source kernel module loaded into the kernel of an open-source operating system, and is sometimes also applied to code running outside the kernel, such as system firmware images, microcode updates, or userland programs. The term blob was first used in database management systems to describe a collection of binary data stored as a single entity.
Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged in a Linux distribution.
Hiawatha is a web server available for multiple platforms. It has been developed by Hugo Leisink since 2002.
FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular open-source BSD operating system, accounting for more than three-quarters of all installed simply, permissively licensed BSD systems.
iXsystems, Inc. is a privately owned American computer technology company based in San Jose, California that develops, sells and supports computing and storage products and services. Its principal products are customized open source FreeBSD distributions, including the discontinued desktop operating system TrueOS and the file servers and network attached storage systems FreeNAS and TrueNAS. It also markets hardware platforms for these products, and develops enterprise-scale storage architectures and converged infrastructures. As part of its activities, the company has strong ties to the FreeBSD community, has repeatedly donated hardware and support to fledgling projects within the BSD community, and sponsors and develops development within FreeBSD, as well as being a sponsor and attendee of open-source community events.
NetBSD is a free and open-source Unix-like operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was forked. It continues to be actively developed and is available for many platforms, including servers, desktops, handheld devices, and embedded systems.
ProFTPD is an FTP server. ProFTPD is Free and open-source software, compatible with Unix-like systems and Microsoft Windows . Along with vsftpd and Pure-FTPd, ProFTPD is among the most popular FTP servers in Unix-like environments today. Compared to those, which focus e.g. on simplicity, speed or security, ProFTPD's primary design goal is to be a highly feature rich FTP server, exposing a large amount of configuration options to the user.
The bio(4) pseudo-device driver and the bioctl(8) utility implement a generic RAID volume management interface in OpenBSD and NetBSD. The idea behind this software is similar to ifconfig, where a single utility from the operating system can be used to control any RAID controller using a generic interface, instead of having to rely on plentiful of proprietary and custom RAID management utilities specific for each given hardware RAID manufacturer. Features include monitoring of the health status of the arrays, controlling identification through blinking the LEDs and managing of sound alarms, and specifying hot spare disks. Additionally, the softraid configuration in OpenBSD is delegated to bioctl as well; whereas the initial creation of volumes and configuration of hardware RAID is left to card BIOS as non-essential after the operating system has already been booted. Interfacing between the kernel and userland is performed through the ioctl system call through the /dev/bio pseudo-device.
