Linux and the GNU system The GNU project started 12 years ago with the goal of developing a complete free Unix-like operating system. "Free" refers to freedom, not price; it means you are free to run, copy, distribute, study, change, and improve the software. A Unix-like system consists of many different programs. We found some components already available as free software--for example, X Windows and TeX. We obtained other components by helping to convince their developers to make them free--for example, the Berkeley network utilities. Other components we wrote specifically for GNU--for example, GNU Emacs, the GNU C compiler, the GNU C library, Bash, and Ghostscript. The components in this last category are "GNU software". The GNU system consists of all three categories together. The GNU project is not just about developing and distributing some useful free software. The heart of the GNU project is an idea: that software should be free, and that the users' freedom is worth defending. For if people have freedom but do not consciously appreciate it, they will not keep it for long. If we want to make freedom last, we need to call people's attention to the freedoms they have in free software. The GNU project's method is that free software and the idea of users' freedom support each other. We develop GNU software, and as people encounter GNU programs or the GNU system and start to use them, they also think about the GNU idea. The software shows that the idea can work in practice. Some of these people come to agree with the idea, and then they are more likely to write additional free software. Thus, the software embodies the idea, spreads the idea, and grows from the idea. By 1992, we had found or written all of the essential major components of the system except the kernel, which we were writing. (This kernel consists of the Mach microkernel plus the GNU HURD. Currently it is running but not ready for users. The first test release was made in 1996.) Then the Linux kernel became available. Linux is a free Unix-compatible kernel initially written by Linus Torvalds. It was not written for the GNU project, but Linux and the almost-complete GNU system made a useful combination. This combination provided all the major essential components of a Unix-compatible operating system, and with some work, people made it into a usable system. It was a variant GNU system, based on the Linux kernel. Ironically, the popularity of these systems undermines our method of communicating the GNU idea to people who use GNU. These systems are mostly the same as the GNU system--the main difference being the choice of kernel. But people usually call them "Linux systems". At first impression, a "Linux system" sounds like something completely distinct from the "GNU system," and that is what most users think it is. Most introductions to the "Linux system" acknowledge the role played by the GNU software components. But they don't say that the system as a whole is a modified version of the GNU system that the GNU project has been developing and compiling since 1984. They don't say that the goal of a free Unix-like system like this one came from the GNU project. So most users don't know these things. Since human beings tend to correct their first impressions less than subsequent information calls for, those users who later learn about the relationship between these systems and the GNU project still often underestimate it. This leads many users to identify themselves as a separate community of "Linux users", distinct from the GNU user community. They use all of the GNU software; in fact, they use almost all of the GNU system; but they don't think of themselves as GNU users, and often they don't think that the GNU idea relates to them. It leads to other problems as well--even hampering cooperation on software maintenance. Normally when users change a GNU program to make it work better on a particular system, they send the change to the maintainer of that program; then they work with the maintainer, explaining the change, arguing for it, and sometimes rewriting it for the sake of the overall coherence and maintainability of the package, to get the patch installed. But people who think of themselves as "Linux users" are more likely to release a forked "Linux-only" version of the GNU program, and consider the job done. We want each and every GNU program to work "out of the box" on Linux-based systems; but if the users do not help, that goal becomes much harder to achieve. How should the GNU project deal with this problem? What should we do now to spread the idea that freedom for computer users is important? We should continue to talk about the freedom to share and change software--and to teach other users to value these freedoms. If we enjoy having a free operating system, it makes sense for us to think about preserving those freedoms for the long term. If we enjoy having a variety of free software, it makes sense for to think about encouraging others to write additional free software, instead of additional proprietary software. We should not accept the idea of two separate communities for GNU and Linux. Instead we should spread understanding that "Linux systems" are variants of the GNU system, and that the users of these systems are GNU users as well as Linux users (users of the Linux kernel). Users who know this will naturally tend to take a look at the GNU philosophy which brought these systems into existence. I've written this article as one way of doing that. Another way is to use the terms "Linux-based GNU system" or "GNU/Linux system", instead of "Linux system," when you write about or mention such a system. Copyright 1996 Richard Stallman Verbatim copying and redistribution is permitted without royalty as long as this notice is preserved.