# Knowing Knoppix/Introducing Knoppix
## Introducing Knoppix

“Knoppix is… so astoundingly useful it's nearly impossible to overpraise” -- slashdot.org

### What is Knoppix?
#### Linux that runs from CD

Knoppix is an astonishingly clever product. It is a single CD that runs Linux on your PC or laptop. It gives you a full graphical desktop with networking, sound, the lot (subject to suitable hardware). No installation is necessary.
Knoppix is excellent for demonstrations, system recovery, or just testing how well the hardware in a given PC is supported. The Knoppix CD is compressed. On-the-fly transparent decompression gives a remarkable 1,600 Mb of software on a single 700 Mb CD.

#### Can be installed on a Hard Disk or a USB key

You can optionally install Knoppix on your hard drive from the Knoppix LiveCD. Type knoppix-installer in a root console when using Knoppix.
For installation on a USB key see http://www.knoppix.net/wiki/USB_Based_FAQ

#### How it works

Start the computer using the Knoppix CD. The existing software on the hard disk will be bypassed. The hard disk may still be accessed read-only. When you have finished using Knoppix, restart and take the CD out. The regular operating system will run as normal.

#### Safe to run

Knoppix leaves your existing software untouched. In fact, Knoppix can run on a computer with no hard disk at all! After running Knoppix, simply take the CD out of the drive. The computer will behave as if nothing has happened.
The general philosophy of Knoppix is to access disks in read-only mode as much as possible. This is ideal for beginners, because it protects against accidents.

#### Personal

Settings and personal files can be saved to a disk, such as a removable USB hard drive stick. This lets you store a personalised Knoppix setup and take it with you everywhere.

#### Free

Most amazing of all, Knoppix is free. The latest version is always available from the Knoppix download page. Not only is Knoppix free as in no charge, it is also free as in freedom. Subject to certain conditions, you are entitled:
* To make unlimited copies.
* To use one copy on as many computers as you like.
* To give unlimited copies to your friends.
* To sell unlimited copies.
* To customise it to suit yourself.
* To redistribute your customised versions.

### What you can do with Knoppix
#### Learn Linux

This book is designed to help you run Linux for the very first time. Knoppix is perfect for newcomers. Linux isn't going away any time soon. That is why learning it is an investment in your time that will pay off for years to come. This book is meant for people who are at least reasonably familiar with computers. For example, I assume you know your way around your computer's mouse, keyboard, CD drive, and so on.

#### Rescue and test

Knoppix is a wonderful tool for rescuing and testing PCs. I will provide enough information to be useful, without going into mind-bending detail. With Knoppix it is possible to:
* Read files from Windows formatted hard disks, even when the operating system installed on the hard disk cannot be started (unless the hard disk has an unrecoverable data error, or if it is physically damaged).
* Copy files onto other disks, such as removable USB drives, Zip drives, CD-RW blanks and network drives (given suitable hardware).
* Identify hardware, even when Windows cannot identify it (subject to certain limitations).

#### Use and explore

Knoppix is a complete desktop system. Use it:
* To print.
* To play music.
* To use a scanner or a digital camera.
* To connect to the Internet.
* To browse the Internet's World Wide Web.
* To send and receive Internet email.
* To try out the built-in office applications, graphics tools, sound playing, video playing, Internet applications and games.

#### Network

Knoppix is a child of the Internet. Knoppix does networking with its eyes closed. For security reasons, Knoppix does not automatically run any servers that could be accessed from the outside.

### Where Knoppix comes from

Knoppix was created in Germany by Klaus Knopper. Knoppix is a volunteer, co-operative, community effort. It exists entirely on the Internet. At the moment Knopper is the man who does most of the work on the disk. He does get patches and some scripts from the community, but he is still the most important person. The Knoppix project is hosted by LinuxTag, which is based in Germany at the Technical University of Kaiserslautern. The LinuxTag team runs conferences, workshops and exhibitions for everyone interested in Linux and Free Software.

### Knoppix is Free Software

Knoppix is Free Software. It is licensed under the GNU General Public Licence (GPL). Free Software is not freeware, and not shareware. Free Software means “free as in freedom”, not necessarily price. This means you are allowed to run, copy, distribute, study, change and improve Knoppix at no charge.
The catch is that when you give (or sell) copies to other people, you must give them the same freedoms under which you received it. This limitation ensures that Knoppix is free now and will remain free forever. For more details, see the license text at the end of this book.

### Limitations
#### No warranty

First and most important of all, Knoppix is experimental software. There is no warranty. Use it at your own risk.

#### CD means slow

Compact Disc Read Only Memory (CD-ROM) drives are much slower than hard disk drives. This means that some applications on the Knoppix CD may take a long time to start; much longer than they would do on a full permanent Linux system. However, Knoppix has some clever (optional) tricks that can spectacularly speed things up.
Knoppix does not get very far on unreliable CD-ROM drives. Since everything has to be loaded from CD, it falls over pretty quickly if CD-ROM errors occur, or if the Knoppix CD itself is damaged. Knoppix has built-in tools for testing its own media.

#### Not everything works

Knoppix supports a huge range of common PC hardware, but not everything. Internal dial-up modems and external USB broadband modems tend not to work. AOL and Compuserve are completely incompatible. Certain cheap printers may be useless. Many cheap colour laser printers do not work. Support for wireless (802.11b) network adapters is limited at best. Certain types of multimedia audio and video files are unplayable. Most commercial DVD movie discs cannot be played. In general, Knoppix does not run Windows software.

#### RAM intensive

Knoppix works by loading everything into Random Access Memory (RAM). The more RAM you have, the better. For typical performance, you need 128 Mb of RAM.
If you are lucky enough to have 828 Mb of RAM or more, Knoppix has clever tricks to make good use of all the RAM in your computer. This can deliver blazingly fast performance.
If you have less than 128 Mb of RAM, Knoppix has the ability to use part of the hard disk as if it were RAM. This is called creating a swap file. However, this technique does not work on all hard disks, and performance is much slower than real RAM.

### What is included in Knoppix?

Knoppix is a compilation of a huge number of works from around the Internet. Some of the projects mentioned in this book are:
| Project | Home page |
| AbiWord word processor | http://www.abisource.com/ |
| Audacity sound recorder | http://audacity.sourceforge.net/ |
| Common Unix Printing System (CUPS) | http://www.cups.org/ |
| Debian distribution | http://www.debian.org/ |
| Gnumeric spreadsheet | http://www.gnumeric.org/ |
| The GNU Image Manipulation Program (The Gimp) | http://www.gimp.org/ |
| GNU utilities | http://www.gnu.org/ |
| The K Desktop Environment (KDE) | http://www.kde.org/ |
| Linux kernel | http://www.kernel.org/ |
| Mozilla web browser | http://www.mozilla.org/ |
| OpenOffice.org office suite | http://www.openoffice.org/ |
| Samba file sharing server for Windows PCs | http://www.samba.org/ |
| Scanner Access Is Now Easy (SANE) | http://www.sane-project.org/ |
| Xine Media Player | http://xinehq.de/ |
| X Multimedia System | http://www.xmms.org/ |
| X Window System | http://www.xfree86.org/ |
Putting it all together is the work of the Debian project. The result is called the Debian distribution. This means that Knoppix is Debian modified to run on a self-contained CD.

### What is Linux?

Linux (pronounced "lin-ucks") is a free operating system. An "operating system" is the base software that makes a computer useful.
Strictly speaking, Linux is the kernel. The kernel is the core component of the operating system. Think of an operating system as a nut. The shell is the part that you use. The kernel is the core that talks to the computer's hardware.

#### A little history

In the 1970s, computer programs were free. A program is a sequence of instructions that makes a “calculating machine” do something useful. The engineers who worked on these instructions became known as programmers. They shared their know-how with each other. They found that it made their work more pleasant.
Unfortunately, this co-operative spirit died under commercial pressures. Restrictive practices in the fast-growing “software industry” meant that sharing the most useful programs and some of the most vital technical information became largely impossible.
A man named Richard Stallman was greatly frustrated by this change. He wanted to bring back the spirit of the early days that he had known at MIT (Massachusetts Institute of Technology). He knew that he had the perfect skills to build a free operating system. He knew that if he didn't do it, no-one would. So he decided to do it, or “die trying”.
By the 1990s, Stallman's Free Software Foundation had found or created nearly all the components of a free operating system. He called his creation “GNU's Not UNIX”.
The name is a joke designed to poke fun at the alphabet soup of computer acronyms. Some acronyms have other acronyms as part of their definition. The GNU acronym takes this one stage further - it has its own acronym as part of its definition. “Is Not” is a way of saying “is like” or “is compatible with”.
UNIX refers to a family of operating systems that were used mainly in science, engineering and finance. Stallman chose to base his efforts on UNIX because it was tried and tested. It would also be convenient for other people to switch from UNIX to GNU.

##### How GNU grew

In 1991, the GNU project still lacked a kernel, the vital core component of an operating system. Luckily, a student in Finland called Linus Torvalds created one “as a hobby”.
In 1991, Torvalds produced a simple, basic system called “Freax”. He called it “Linux” privately but never meant it to be called that in public, because he didn't want to be too egotistical. He made it free because he wanted feedback. It was posted on the Internet by a friend.
Pretty soon, Torvalds began receiving email from places he'd dreamed of visiting, like Australia and the United States. Instead of cash, Linus preferred postcards. His sister Sara was suddenly impressed that her brother was somehow hearing from new friends far away.
Torvalds had used the Free Software Foundation's tools, so he decided to make it free likewise. This was a way to say “thank you”. He decided to put Linux under the Free Software Foundation's General Public Licence. This meant that anyone could use, improve or sell Linux, but no-one could take overall control.

##### It's a GNU world!

From there, it snowballed in the most extraordinary way. It has catapulted Torvalds to accidental super-stardom. He has appeared on the cover of Time magazine. We should remember that Stallman started it all. That is why the full title of Linux is GNU/Linux. In other words, Knoppix is a Linux-based GNU system.