Free software

[7][2] Computer programs are deemed "free" if they give end-users (not just the developer) ultimate control over the software and, subsequently, over their devices.

While this is often called "access to source code" or "public availability", the Free Software Foundation (FSF) recommends against thinking in those terms,[9] because it might give the impression that users have an obligation (as opposed to a right) to give non-users a copy of the program.

Users are thus legally or technically prevented from changing the software, and this results in reliance on the publisher to provide updates, help, and support.

According to the Free Software Foundation, "Open source" and its associated campaign mostly focus on the technicalities of the public development model and marketing free software to businesses, while taking the ethical issue of user rights very lightly or even antagonistically.

The BSD-based operating systems, such as FreeBSD, OpenBSD, and NetBSD, do not have their own formal definitions of free software.

Users can easily download and install those applications via a package manager that comes included with most Linux distributions.

Some of the best-known examples include Linux-libre, Linux-based operating systems, the GNU Compiler Collection and C library; the MySQL relational database; the Apache web server; and the Sendmail mail transport agent.

In United States vs. IBM, filed January 17, 1969, the government charged that bundled software was anti-competitive.

In 1983, Richard Stallman, one of the original authors of the popular Emacs program and a longtime member of the hacker community at the MIT Artificial Intelligence Laboratory, announced the GNU Project, the purpose of which was to produce a completely non-proprietary Unix-compatible operating system, saying that he had become frustrated with the shift in climate surrounding the computer world and its users.

In his initial declaration of the project and its purpose, he specifically cited as a motivation his opposition to being asked to agree to non-disclosure agreements and restrictive licenses which prohibited the free sharing of potentially profitable in-development software, a prohibition directly contrary to the traditional hacker ethic.

In 1983, Richard Stallman, longtime member of the hacker community at the MIT Artificial Intelligence Laboratory, announced the GNU Project, saying that he had become frustrated with the effects of the change in culture of the computer industry and its users.

The manifesto included significant explanation of the GNU philosophy, Free Software Definition and "copyleft" ideas.

The Linux kernel, started by Linus Torvalds, was released as freely modifiable source code in 1991.

FreeBSD and NetBSD (both derived from 386BSD) were released as free software when the USL v. BSDi lawsuit was settled out of court in 1993.

[32] It is rare that a license announced as being in-compliance with the FSF guidelines does not also meet the Open Source Definition, although the reverse is not necessarily true (for example, the NASA Open Source Agreement is an OSI-approved license, but non-free according to FSF).

Proponents of permissive and copyleft licenses disagree on whether software freedom should be viewed as a negative or positive liberty.

Also, since the blobs are undocumented and may have bugs, they pose a security risk to any operating system whose kernel includes them.

[46] As of October 2012[update], Trisquel is the most popular FSF endorsed Linux distribution ranked by Distrowatch (over 12 months).

[47] While Debian is not endorsed by the FSF and does not use Linux-libre, it is also a popular distribution available without kernel blobs by default since 2011.

Free software business models are usually based on adding value such as customization, accompanying hardware, support, training, integration, or certification.

[51] Fees are usually charged for distribution on compact discs and bootable USB drives, or for services of installing or maintaining the operation of free software.

Development of large, commercially used free software is often funded by a combination of user donations, crowdfunding, corporate contributions, and tax money.

"[53] Microsoft CEO Steve Ballmer stated in 2001 that "open source is not available to commercial companies.

[citation needed] Free software played a significant part in the development of the Internet, the World Wide Web and the infrastructure of dot-com companies.

[59] "We migrated key functions from Windows to Linux because we needed an operating system that was stable and reliable – one that would give us in-house control.

The economic viability of free software has been recognized by large corporations such as IBM, Red Hat, and Sun Microsystems.

[62][63][64][65][66] Many companies whose core business is not in the IT sector choose free software for their Internet information and sales sites, due to the lower initial capital investment and ability to freely customize the application packages.

[68] Eric S. Raymond argued that the term free software is too ambiguous and intimidating for the business community.

Raymond promoted the term open-source software as a friendlier alternative for the business and corporate world.

An operating system's computer screen, the screen completely covered by various free software applications.
GNU Guix . An example of a GNU FSDG complying free-software operating system running some representative applications. Shown are the GNOME desktop environment the GNU Emacs text editor, the GIMP image editor, and the VLC media player .
This Euler diagram describes the typical relationship between freeware and free and open-source software (FOSS): According to David Rosen from Wolfire Games in 2010, open source / free software (orange) is most often gratis but not always. Freeware (green) seldom expose their source code. [ 13 ]
Diagram of free and nonfree software, as defined by the Free Software Foundation. Left: free software, right: proprietary software, encircled: gratis software
Copyleft , a novel use of copyright law to ensure that works remain unrestricted, originates in the world of free software. [ 29 ]
Although nearly all computer viruses only affect Microsoft Windows , [ 36 ] [ 37 ] [ 38 ] antivirus software such as ClamTk (shown here) is still provided for Linux and other Unix-based systems, so that users can detect malware that might infect Windows hosts.