Unix
The predecessor of Unix was Multics, and Bell Labs was involved in the development of the operating system, but because of the slow pace of development, Bell Labs decided to abandon the plan. Bell Labs engineers, Thompson and Ricky, developed UNIX on their own. The first edition of Unix was written in PDP-7 assembly language. And in 1971 co-invented the C language. 1973 Thompson and Ricky Rewrite Unix in C to form the third edition of Unix.
GNU
Unix is the name of a widely used commercial operating system. All the software on it is proprietary software and charges are required. and GNU will implement the UNIX system interface standards, and UNIX on the same patent software, but are free.
For example:
Emacs.
GNU C Compile GCC
GNU C Library GLIBC
Bash Shell
GPL GNU general public License
in order to ensure that GNU software is free to "use, reproduce, modify and distribute", all GNU software has an agreement to grant all rights to anyone in the event that no restrictions are added to any other person.
FSF (Free Software Foundation) Freedom Software Foundation.
provide technical, legal and financial support for the GNU program. Although the GNU program is largely voluntary and unpaid by individuals, the FSF sometimes hires programmers to help write. As the GNU program began to gain success, some commercial companies began to intervene in development and technical support. The most famous is Cygnus Solutions, who was later merged by Red Hat.
Linux
Minix: Similar to UNIX-like systems, the gas is modeled after the Minix system to write its own kernel Linux 0.02. At the same time, in order to take into account that some Unix running software can run on Linux, modify the Linux kernel, refer to the standard POSIX specification. Soon Linux and Unix are compatible to share all the software.
POSIX represents a portable operating system interface (Portable Operating system Interface, abbreviated as POSIX), and the POSIX standard defines the interface standards that the operating system should provide for applications. is the generic term for a series of API standards that are defined by the IEEE for Software to run on a variety of UNIX operating systems.
Linux Distributions
the advent of Linux has been completely released by GNU project developers, because without their own kernel programs before Linux, their free software can only run on UNIX.
in order for users to reach out to Linux, many commercial companies have formed Linux distribution the kernel (Kernel) and the running GNU Software (softwares) and their own creative tool programs (tools).
Currently, Linux distributions is divided into two major systems, a system that uses RPM to install software, including the Red Hat,fedora. There is also a system for installing software using Debian's Dpkg method, including Debian,ubuntu.
Linux Past Life
