what is freebsd

what is FreeBSD?

If you also have a question in your mind about what is FreeBSD? Today’s article will answer all your questions about Free BSD.

You must have asked yourself why FreeBSD is recently used in large and high-traffic servers? And why do we hear its name more these days, and why is it so important?

First, we must say that Free BSD is a multipurpose operating system similar to Unix, which is open source and free. Most users know it as a distribution of Linux Because it has many similarities with Linux. In the following, we will examine the FreeBSD operating system in detail. We will explain everything about FreeBSD and will introduce you to its features and advantages, as well as the different versions of FreeBSD and its history.

Introducing the Free BSD operating system

FreeBSD is an open-source Unix-like operating system and a popular multipurpose server platform; This operating system is used for laptops, PCs, and servers. It should be noted that although FreeBSD is directly derived from Unix, it cannot be called Unix; Because currently, “Unix” is a registered trademark for Open Group.

FreeBSD was developed by the FreeBSD project and based on the Berkeley BSD software distribution. Free BSD is one of the company’s operating systems, which, like Ubuntu, is freely available so that everyone can access its source codes, it is developed. Therefore, developers can add features to this platform without restrictions and make important changes based on the base code in the versions created on this platform. As a result of this advantage, Various versions of FreeBSD and commercial products are marketed.

The main goal of FreeBSD is to provide a multi-purpose, fast and stable operating system that meets every need and focuses most on performance, networking, storage, stability, and speed; FreeBSD with its unique features, such as a very high-performance speed that is incomparable to other competitors and its high flexibility and security, It has attracted the attention and interest of many users.

The FreeBSD operating system is compatible with many hardware and architectures, and like other members of the BSD family, it has the FreeBSD kernel and all its user space programs, such as the shell and commands such as cat and ps, are all kept in a source code repository. It is interesting to know that the binary files of other operating systems, including Linux, can be run in FreeBSD. All Additional applications can be installed through FreeBSD ports and packages.

This operating system, in addition to its strong performance in the desktop field; supports network services such as web, e-mail, and other applications, and it is mostly used as an Internet server because reliability is one of its most prominent features; For this reason, two famous companies, Netflix and Sony, chose FreeBSD to provide reliable services for their PlayStation consoles.

FreeBSD is the most famous and popular operating system of the BSD series, which has the largest user community in the BSD family, But it is not the only member of this family, and there are other operating systems in the BSD family are used to perform project work;  for example, NetBSD operating system, OpenBSD operating system, and DragonFly BSD operating system, which we will briefly explain in the following.

NetBSD operating system: This operating system is a sub-branch of the BSD series, which is compatible with any type of hardware, and by using pkgsrc, it removes all installation and execution restrictions for applications, especially Solaris, and allows any application to be installed.

OpenBSD operating system: This operating system was developed to maintain and improve security and has many practical features, such as having OpenSSH (the same as SSH server), which is considered an excellent feature for remote access.

Today, many people and commercial companies use FreeBSD for various purposes, including Yahoo, Apple, Juniper Networks, Nokia, IBM, Yandex, Apache Software Foundation, Hotmail, Sony, and many others.

History of the FreeBSD operating system

AT&T licensed the Unix source code to the University of California, Berkeley, in 1974. The Computer Systems Research Group then updated and improved AT&T’s Research Unix, calling it the Modified version of Berkeley Unix or Berkeley Software Distribution (BSD). Bill Joy started the BSD project in 1976; the purpose of BSD was to provide technologies such as TCP/IP, virtual memory, and the Berkeley Fast File System. In June 1989, the project released the first public version of BSD, Networking Release 1, or Net-1 for short.

FreeBSD, which is from the BSD family, was invented in 1992 based on an old project called BSD by a software team between 1975 and 1993 at the University of California at Berkeley (named after Jordan K. Hubbard, Grimes, Williams) and with the original name of 386BSD Patch kit. Then, by adding many features and solving the problems of this operating system, this team designed a new version of it called 386BSD 0.5. Finally, in 1993, a person named David Grayman in Walnut Creek, California built and launched a new operating system called FreeBSD 1.0 based on its old version, namely Patch kit, with the cooperation of its original creator, Hubbard, which became known as the first official version of FreeBSD.

After that, from 1994 onwards, more complete versions of it were presented by Walnut Creek under the titles of 4th and 5th editions. According to Jordan Hubbard, this operating system was created to provide independent and general-purpose software. Providing the FreeBSD source code to users has enabled users to use this system freely, so users and developers experience more freedom in this operating system. In this way, this operating system is not only limited to the GPL license, which is specific to open source developers, but also grants a freer license to use the source of the program called FreeBSD License to its enthusiasts.

Also, David Grayman, to confirm Jordan Hubbard’s words, introduced FreeBSD as a powerful operating system and the best platform for large local and internet servers and referred to Yahoo’s contract as the first famous company that chose this operating system for its main servers, such that this site sends more than half a billion web pages to web users every day, which shows the power and speed of the systems it uses; Introduced FreeBSD as a reliable and powerful operating system.

It is interesting to know that Hotmail as a free e-mail service that is one of the creators of server operating systems; it uses a combination of Windows, Solaris, and FreeBSD to cover more than 30 million users worldwide. According to the tests carried out by Walnut Creek of its operating system, this operating system has managed to transfer two terabytes of information on the Internet in 24 hours, which is considered a record of its kind.

Features of FreeBSD

  • Multi-user access, which means, in the FreeBSD operating system, several users can perform tasks and use peripherals in a shared manner without disrupting each other’s work.
  • A multitasking operating system that enables users to run multiple processes simultaneously and dynamically prioritize each process to ensure that each process consumes its fair share of resources.
  • Having a memory protection mechanism is intended to prevent disruption when performing tasks simultaneously so that if a problem occurs in one process, it does not affect another.
  • The possibility of loading new types of files that provide network protocols or binary simulators without the need to create a new kernel in the system.
  • Provides the possibility to communicate with different systems using TCP/IP connections. With the help of this feature, in addition to FreeBSD acting as the main server, it can perform tasks such as FTP, firewall, email services, and network file system.
  • FreeBSD support for a wireless network and IPv6 protocol and CARP protocol for multiple devices to use a common IP address, which makes this operating system superior when there is a disruption in a service system, and with the help of this feature, other systems can continue their activities and do not be affected by the disrupted system.
  • Support for Ports Collection includes 23,000 third-party apps that will satisfy your need for various third-party apps.
  • FreeBSD kernel supports various tasks such as process management, communications, booting, and file systems. The FreeBSD kernel is integrated, has a modular design with unique capabilities, and uses modules to design different parts of the kernel, including drivers.
  • High security, the security of FreeBSD is provided by 3 firewalls named PF, IPFW, and IP filter(IPF); IPFW firewall is specific to FreeBSD itself; this firewall is embedded as a module in the FreeBSD kernel and uses the DummyNet function; as a result, administrators with The use of this feature can simulate unfavorable network conditions such as delay, packet loss, and bandwidth limitations.
  • Ability to run DTrace, which is a troubleshooting tool for performance analysis.
  • Support various file systems in addition to the Unix file system, including FAT32 and NTFS, SMBFS, ext2, ZFS, ISO9660, and network file systems, which are considered as information storage frameworks in FreeBSD.
  • FreeBSD jails are a security mechanism and virtualization solution at the operating system level through which programs can be run in a safe and quarantined environment; It means that any process that runs inside this environment cannot communicate with the process outside this environment.


Features of freeBSD


Familiarity with FreeBSD versions

FreeBSD has released 13 versions, the first of which was released as  FreeBSD1.1 released in November 1993 at the same time as the Ports Collection (which includes features related to ports). The first version of FreeBSD had features such as fixing problems related to 386BSD import and adding ported programs such as XFree86, XView, InterViews, elm, and NNTP.

Version  FreeBSD2.2 was released on November 22, 1994, and was most commonly used on Internet servers; This distribution introduced important changes compared to the first version of FreeBSD. Including;

  • It used NetBSD as the kernel module.
  • It had phkmalloc instead of BSD malloc.
  • ELF feature is used for Linux simulation.
  • It supports MS-DOS, UnionFS, and Kernfs system files.
  • BSD-Lite 4.4 is used to replace the code base.

With these changes applied to the second version of FreeBSD, which was widely used for general purposes in its time, FreeBSD released the third version, FreeBSD3.3, on October 16, 1998, which which was the first sub-branch to enable symmetric multiprocessing (SMP) systems through the use of Giant locks and specified the move from a.out to ELF executables. Also, FreeBSD 3.1 introduced USB functionality for the first time.

In March 2000, FreeBSD 4 became the preferred operating system for web and ISPs due to its reliability and performance and it was known as the most reliable operating system of the Unix family among hosting providers.

On January 14, 2003, FreeBSD 5.5 was the seal of approval for the operating system’s reliability in future FreeBSD 5. x distributions, which added Bluetooth support and encryption by default in the operating system

On November 1, 2005, Release FreeBSD6.6  included optimizations, threading, and SMP changes, increased network performance, and support for hardware performance countering (HWPMC).

After 3 years of using FreeBSD 6, FreeBSD 7 was released on February 27, 2008; It attracted users’ attention with features such as ARM, jemalloc, SCTP, UFS journaling, experimental port of ZFS Sun file system, GCC4, and updating and optimizing the main network and SMP performance, etc.

FreeBSD8 version released in 2009 added a new virtualization container called “vimage” to the FreeBSD platform, supported USB 3.0, and rewrote the FreeBSD netisr framework to support threading. FreeBSD updated TTY with its new instance to provide ideal resource management and support for SMP.

FreeBSD version 9, released on January 12, 2012, introduced the BSDInstall installer, which was used with the help of the ISO images included in this version. This version of FreeBSD also included changes such as:

  • Support for NFSv3 and NFSv2 from NFSv4
  • Upgrade ZFS version to version 28
  • Implementation of HAST storage framework
  • Support for Softupdates journaling by Fast Filesystem

With our explanations, it is clear that FreeBSD has always tried to fix problems and add new features by providing new distributions.

FreeBSD 10 also released new features; It enabled Capsicum in its core by default and added Raspberry Pi support.

On October 10, 2016, the stable version of FreeBSD 11 was released, and with it, a new version of NetMap was introduced, which provides the ability to install the ZFS file system and support for ARM 64-bit.

FreeBSD version 12 came with changes to the way graphics drivers are used on amd64 and i386 platforms, and in this version, the ext2fs file system was upgraded to enable complete read/to write capability for the ext4 file system.

And finally, the last version of FreeBSD was released with FreeBSD 13 on April 13. Of course, 13 versions of FreeBSD have been released so far, and this cycle will continue. In this version, we see improvements to move to a new OpenZFS file system and access to new features to complement and grow the FreeBSD 13 platform, which will improve system performance by abandoning support for outdated drivers. This version prioritizes Cleaning the code base and performance improvements.

Applications of the FreeBSD operating system

The uses of FreeBSD are varied and extensive, but we will mention a few of the most useful ones:


FreeBSD is used as an email server, web server, FTP server, firewall, DNS, router, etc.

Commercial use

Because FreeBSD provides a lot of freedom to users and commercial companies, it enables users to use the FreeBSD source code in proprietary products of commercial companies.


In the FreeBSD environment, it is possible to use different desktops such as GNOME and KDE, as well as the possibility of installing the X window system. For users’ convenience, some projects such as PC-BSD provide custom versions of FreeBSD with a graphical environment by default.

Embedded systems

Along with providing common hardware such as x86 and x86-64, FreeBSD supports other hardware platforms and architectures such as ARM, MAPS, PowerPC, etc., which is used in Embedded systems due to this feature.

Advantages of FreeBSD

For many users, the reason for the popularity and use of the FreeBSD operating system as the infrastructure of many famous and powerful systems such as Netflix may be a question. We have decided to introduce you to the advantages of the FreeBSD operating system so that you know the reasons for its superiority and popularity.


Security is always the most important factor for users; FreeBSD developers have made many efforts to protect this operating system from damage and increase the security of FreeBSD by providing features to improve the security.

FreeBSD provides its security through 3 firewalls, PF, IP firewall, and IP filter; from version 5 onwards, in addition to supporting the access control list provided by the TrustedBSD project (TrusteDBSD is a project that was created in April 2000 to add advanced security features to FreeBSD.), to improve security, it added and developed advanced features such as OpenBSM, OpenPam and mandatory access control to this platform. This project is supported by organizations and companies such as DARPA, the University of Pennsylvania, Yahoo!, Google, Apple, etc.

FreeBSD’s use of the OpenSSH program by default during installation was one of this operating system’s other security methods, and this program’s effectiveness in protecting important information during remote communication is undeniable. FreeBSD encrypts sensitive information such as passwords and usernames that are sent over the network with its security solutions. Data encryption in FreeBSD is done at the level of sectors and block disks by the GELI and GBDE frameworks embedded in the hardware.

Also, in the FreeBSD environment, with the help of the Portaudit tool, the user can prepare a report of security vulnerabilities about the programs installed on the system and check and fix the potentially dangerous ones.

Unix and BSD, with a 20-year reputation in security, have a good industry reputation as stable and secure platforms.

Easy installation

Installing the FreeBSD operating system has become very easy for all users, from beginners to professionals, by providing training packages and complete documentation that are detailed installation guides. Also, FreeBSD’s installation process is uncomplicated. It is easily installed either through DVD, CD or directly through NFS or FTP. Access to reliable educational resources eliminates possible concerns for users, especially beginners.

Being free

Being free is a great advantage to be able to use a special and secure operating system with these features without paying for it.

FreeBSD operating system is also available to users for free; however, it is unbelievable that this operating system provides access to its source code to users so that anyone can make the best use of it as they wish. They can use its capabilities by downloading the FreeBSD operating system free from Freebsd.org.


Stability is the second most important factor after security for any operating system so that you can use the operating system to do important tasks without any problems. The FreeBSD operating system has been running stably on servers for years and has not encountered any problems so far. The security and stability of the FreeBSD operating system is a decisive answer to why it is popular and preferable to competing operating systems.

The possibility of simultaneous storage on two separate computers

One of the excellent advantages of FreeBSD is the possibility of storing information on two hard disks in two separate computers with very high availability. FreeBSD makes this feature possible by supporting NTFS, FAT32, SMBFS, ext2, and network file systems. The main storage framework in FreeBSD is the ZFS file system, which includes features such as compression, quotas, and prevention of duplicate data storage on disk, and was supported in FreeBSD from version 7 onwards.

all about FreeBSD

Disadvantages of FreeBSD

Like other operating systems, FreeBSD is not absolute perfection. It also has flaws that we want to mention, but we must say that the advantages of FreeBSD are so pleasant that few people pay attention to its flaws.

  1. It is less compatible with different types of hardware.
  2. It does not support plug-and-play.
  3. It does not have strong support from developers.
  4. Working with FreeBSD operating system has a complexity that is problematic for beginners.

Because FreeBSD is complicated and challenging to work with its environment, even if it has an attractive user interface, this is an essential concern for beginners. In addition to this problem, with poor support from developers, beginner users cannot solve their problems. Therefore, it is better to keep these things in mind.

Similarities and differences between FreeBSD and Linux operating systems

The FreeBSD operating system is compared in many ways to its competing operating systems, such as Linux, and although they have many similarities, there are fundamental differences between them.

similarities between Linux and FreeBSD

  • They are Unix-like; although FreeBSD has evolved over time with numerous updates and changes from the Unix operating system, Linux was developed as an alternative to Unix.
  • They are open source and free, and users can access the source code of these operating systems and apply changes as they wish.
  • The design of their operating system is standard, and they have a similar pattern, and the division of the file system hierarchy is similar.
  • They have similar shell environments, which is the main method of interaction of both operating systems.
  • They have the same API programming feature.

Due to the similarities between FreeBSD and Linux operating systems, these two operating systems can easily communicate with each other and share various programs and tools. Still, Linux is more prevalent in the market compared to FreeBSD operating system.

The differences between Linux and FreeBSD

Some of the differences are as follows:

Difference in license

FreeBSD and Linux differ in licensing because the FreeBSD operating system has a special BSD license, which covers the FreeBSD kernel and all its tools. While all Linux programs, Linux kernel, and Linux distributions are based on the GNU GPL license.

Now we want to know what is the difference between these two licenses in terms of being allowed? We must say that they are not different and are almost similar to each other. In the BSD license, anyone can make changes or share it with access to the source code. Also, the GNU GPL license provides users with a free and open-source ecosystem. In this situation, it is necessary for proprietary software to be based on the GNU license, So that there is no problem. But the softwares with a BSD license can be freely and without problems included in proprietary softwares and their source. with this feature of the BSD license, most businesses rely on BSD licensed software to commercialize their software because they are able to sell the software directly while keeping the source.

Differences in goals and history

Another difference between Linux and FreeBSD is in their history and goals, and originality; Linux was founded by Linus Torvalds at the University of Helsinki with educational purposes to replace MINIX, and after combining the Linux kernel with various GNU components, an operating system similar to Unix was created; As a result, Linux has been developed independently without having Unix features, while FreeBSD is an extended version of the Unix operating system and is closely related to Unix operating system and developed the features of the AT&T Unix operating system, which also had a license, but Later, to avoid users having to obtain an AT&T license, they replaced it with open source options, and as a result, all AT&T Unix components were rewritten under the BSD license.

FreeBSD got rid of licensing restrictions by going through a long process. but still, it keeps its connection with its past; they also invested in creating this system by referencing the Unix method, believing that FreeBSD would always operate under an explicit license from Unix.


FreeBSD performs flawlessly with its features in the network and the ability to transfer information. The use of famous sites such as yahoo, Free software, Qwest, and Hotmail from this operating system shows its excellent performance. Linux also has a unique processing speed and efficiency; however, in a test, this operating system in a high-traffic and crowded network environment, its performance was approximately 20-30% weaker than its competitor, FreeBSD, although the makers of the Linux kernel claim that this weakness through version 4.2 of the Linux kernel, which, like Free BSD, has a virtual container is resolved.

However, both operating systems are always developing and growing due to being open-source and they will not be fundamentally different due to being modeled on each other.


In terms of reliability, FreeBSD leaves no room for doubt for users, especially in the execution of database-related processes; it has high reliability; Also, Linux has been reliable in terms of stability and reliability from the past to the present day and is famous among experts in this field, But if we want to compare these two operating systems, FreeBSD offers better performance for large disk I/O applications. functional weakness in Linux is due to the non-synchronous implementation of this operating system, which always brings the possibility of problems with electrical fluctuations or possible outages.

Separation of the main operating system from additional software

Another difference between Linux and FreeBSD is in the system area in terms of system development and design. The FreeBSD kernel and operating system are developed in a coherent and integrated manner, but the technical focus in Linux is only on the kernel, and other components are derived from various sources. You might say to yourself that this is not a big difference, but in practice, it makes the way of managing and interacting with the system different.

In Linux, developers intend to improve the performance of a set of components that originate from various repositories and sources; So that a distribution may maintain different repositories based on which teams are responsible for certain packages, and the development team’s concern is only a subset of software, but the main task of FreeBSD is to maintain a main operating system. In this operating system, the developers have created a core and a set of software and maintain them as an integrated and coherent unit; For this reason, when we face a problem and need to replace a part of the whole set, we will face a problem. But on the other hand, FreeBSD has more reliability due to its integration, and operating system management will be more accurate in this environment.

It should be noted that FreeBSD, like Linux, offers a set of optional software with the possibility of separate management and updates the main system and optional software separately.

File system

FreeBSD uses the Unix File System (UFS), which is more advanced and complex than the Linux file system (2ext) and also performs asynchronous disk reading and writing operations (Asynchronous I/O) better. ّFreeBSD With File Flag, it prevents the deletion of a specific file and the reading and writing of damaged tracks on the disk and limits any changes in the contents of a file or directory. Still, The file system used by Linux also works very well, but its weakness is a lack of stability. It is possible that a problem during the mount can damage a part of a file system and cause the loss of information in that part.

being safe

FreeBSD has won the trust of experts and users in terms of security, and all its modules and components have been reviewed and tested many times. FreeBSD has embedded different levels of security inside its kernel, and it has provided the system administrator with the ability to specify the kernel’s internal functions and the user’s access level. In addition to these measures, FreeBSD has a Firewall mechanism, Packet Filling, and many intrusion detections and tracking tools to increase security.

Linux is also known for its security. Users know it as the most secure operating system that secures its operating system through firewalls and numerous IDS tools, but due to the open-source of Linux, which has enabled the development of this operating system for all users, including beginners, and also Due to the different goals and priorities of users and companies interested in Linux development, some of them may prefer efficiency to security, the security of this operating system is unstable. As a result, the Linux operating system is less secure compared to FreeBSD.

Development environment

In FreeBSD, the development and programming environment is designed to be compatible with various Java, Perl, and Python programming software and has a powerful environment for the C++ language. These softwares are also supported by Linux, but if a program is compiled with a Linux such as RedHat, it will not run in another Linux like Slackware.


Linux is supported by its developers such as Redhat and Mandrake, and this community support this operating system when a problem occurs to solve it, and FreeBSD is supported by many sites and companies and provides free services to users.

Free Softwares

Linux and FreeBSD have many free and open-source applications that are growing, and these two operating systems also support many programs as GNU software that can be installed and run for free.

In FreeBSD, to access open-source software, there is a unique library called FreeBSD Ports Collection as the best resource to access. In Linux, limited programs called shareware are offered for free, but they have limitations and are not provided to users with the source code; for this reason, designers and developers will be unable to make changes in the direction of troubleshooting, solving problems, and optimizing software.


FreeBSD has made it possible to install binary (closed source) and open-source drivers, but hardware manufacturers, especially those manufacturers that provide low-cost, high-volume hardware, are only interested in providing drivers Under the Windows operating system. About Linux, this operating system only installs open-source drivers, and the problem is those driver manufacturers who even offer non-Windows drivers are reluctant to produce open-source drivers.


FreeBSD is developing and expanding rapidly in this field and is compatible with many applications; it can even run programs compiled with UNIX, such as SCO or Linux. Linux is also similar to FreeBSD in this sense, but with the difference that it cannot run programs compiled for FreeBSD and Unix.

In general, these two operating systems are based on Unix, are free and open-source, and have many similarities; To choose the best operating system between Linux and FreeBSD, you should consider your interest, goals, and experience in using the operating system. When ordering a Linux VPS, If you are looking for a powerful core, the Linux operating system and its distributions are ideal, but if you want a reliable and stable operating system for powerful servers in busy networks, FreeBSD is the best choice.


FreeBSD is a common and popular distribution of the BSD family for desktop and server and all systems, but FreeBSD provides the best performance on the server.

In general, FreeBSD has better performance, higher speed, especially in processing inputs, and higher security, and it has better performance and stability for servers in high-traffic networks. That's why many famous sites like Netflix, Apple and Cisco have chosen FreeBSD for their powerful system.

The FreeBSD operating system provides optimal performance for servers, desktops, commercial use, and embedded platforms, developed by a large community over many years.


In this article, we tried to clear all the ambiguities created in your mind and thoroughly familiarize yourself with the popular FreeBSD operating system. FreeBSD is a safe, powerful, and open-source operating system that is derived from the Unix operating system and has the same capabilities and features as Linux and has unparalleled performance in the server field. Due to its high stability and security, it is the choice of most users to operate in the area of servers, especially in high-traffic networks.

After reading this article, I hope there is no question about the FreeBSD operating system.

Thank you for being with us.


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