1. The UNIX Time-sharing system
Linux - History
The UNIX Time-sharing system
Developed in 1969 by Ken Thompson and Dennis Ritchie at AT&T Bell Labs.
Initially written in assembly but was shortly rewritten in C.
Designed to be portable, multi-tasking, and multi-user

2. Linux - History The C Programming Language
Developed for UNIX, has since spread to other platforms.
Designed as a system implementation language, but become widely used in applications.
Many different languages use similar language syntax

3. Linux - History The GNU Project MINIX Founded by Richard Stallman
Goal: Develop a free, open-source UNIX compatible OS
MINIX
Developed by Andrew S. Tanenbaum
Developed as an educational tool to teach students about Operating Systems, at a time when Unix source code was not freely availible

4. Linux - History Linus Torvalds Linux Today
1991, As a graduate student created his own OS kernel to learn about the Intel chip, the initial version of Linux.
Developed up to version 0.02 by himself.
Later released Linux under the GPL license.
POSIX Compliant
Linux Today
Over 1 million lines of code… and growing.
Millions and millions of users.
Version 2.6.x

5. Linux vs. Windows Linux is open source Linux is free
Linux is UNIX based
Bazaar vs. Cathedral
Many different distributions of Linux
Linux architecture is directory base

6. The Linux Kernel
Version 0.01 (May 1991) had no networking, ran only on compatible Intel processors and on PC hardware, had extremely limited device-drive support, and supported only the Minix file system
Linux 1.0 (March 1994) included these new features:
Support for UNIX’s standard TCP/IP networking protocols
BSD-compatible socket interface for networking programming
Device-driver support for running IP over an Ethernet
Enhanced file system
Support for a range of SCSI controllers for high-performance disk access
Extra hardware support
Version 1.2 (March 1995) was the final PC-only Linux kernel

7. Linux Licensing
The Linux kernel is distributed under the GNU General Public License (GPL), the terms of which are set out by the Free Software Foundation
Anyone using Linux, or creating their own derivative of Linux, may not make the derived product proprietary; software released under the GPL may not be redistributed as a binary-only product

8. Design Principles
Linux is a multiuser, multitasking system with a full set of UNIX-compatible tools
Its file system adheres to traditional UNIX semantics, and it fully implements the standard UNIX networking model
Main design goals are speed, efficiency, and standardization
Linux is designed to be compliant with the relevant POSIX documents; at least two Linux distributions have achieved official POSIX certification
The Linux programming interface adheres to the SVR4 UNIX semantics, rather than to BSD behavior

9. Components of a Linux System

10. Components of a Linux System
Like most UNIX implementations, Linux is composed of three main bodies of code; the most important distinction between the kernel and all other components
The kernel is responsible for maintaining the important abstractions of the operating system
Kernel code executes in kernel mode with full access to all the physical resources of the computer
All kernel code and data structures are kept in the same single address space

11. Components of a Linux System (Cont.)
The system libraries define a standard set of functions through which applications interact with the kernel, and which implement much of the operating-system functionality that does not need the full privileges of kernel code
The system utilities perform individual specialized management tasks

12. Major Linux Distributors
Mandrake Linux
Slackware Linux
SuSE Linux
Turbo Linux
Vector Linux
Caldera Linux
Corel Linux
Debian Linux
Kondara Linux
Red Hat Linux

13. The Advantage of Linux Low purchase cost Open Source Software (OSS)
UNIX heritage
Multi User
Scalability
Vendor support
Reliable uptime
Security
Logging System

14. The Disadvantage of Linux
Step learning curve as Implementation
Without standard Hardware support
End-user applications

15. A Comparison Of Win 9x, NT, and Linux
Win NT
Win 9x
Feature
Good
Poor
Scalability
Excellent
Desktop App. Support
None
Enterprise App. Support
Hardware Support
Licensing Cost
Network Performance
Security

16. Linux File system Hierarchy
Essential Binary Files
/bin
Boot Loader Files
/boot
Device Files
/dev
Configuration Files
/etc
User Home Directories
/home
Shared Libraries and Kernel Modules
/lib
Mount Point for Temporarily Mounted FS
/mnt
System Information Virtual File System
/proc
root User Home Directory
/root
Essential System Binaries
/sbin
Temporary Files
/tmp
Shareable Files
/usr
Non-Shareable Files
/var