1)multitasking: several programs running at the same time is called multitasking.

2)multiuser: several users on the same machine at the same time through different terminals/from remote hosts.


3)multiplatform: runs on many different CPUs, not just Intel like AMD too.
 

4)multiprocessor: SMP(Symetri multi processing) support is available on the Intel and SPARC platforms (with work currently in progress on other platforms), and Linux is used in several loosely-coupled MP applications.
 

5)multithreading: has native kernel support for multiple independent threads of control within a single process memory space.


6)runs in protected mode on the 386. ie Protected mode has a number of new features designed to enhance multitasking and system stability, such as memory protection, and hardware support for virtual memory as well as task switching It is sometimes abbreviated p-mode and also called Protected Virtual Address Mode

7)has memory protection between processes, so that one program can’t bring the whole system down.
 

8)demand loads executables: Linux only reads from disk those parts of a program that are actually used.
 

9)shared copy-on-write pages among executables. This means that multiple process can use the same memory to run in. When one tries to write to that memory, that page (4KB piece of memory) is copied somewhere else. Copy-on-write has two benefit’s: increasing speed and decreasing memory use.
 

10)virtual memory using paging (not swapping whole processes) to disk: to a separate partition or a file in the filesystem, or both, with the possibility of adding more swapping areas during runtime (yes, they’re still called swapping areas). A total of 16 of these 128 MB (2GB in recent kernels) swapping areas can be used at the same time, for a theoretical total of 2 GB of useable swap space. It is simple to increase this if necessary, by changing a few lines of source code.
 

11)a unified memory pool for user programs and disk cache, so that all free memory can be used for caching, and the cache can be reduced when running large programs.
 

12)mostly compatible with POSIX, System V, and BSD at the source level.
 

13)POSIX job control.
 

14)pseudoterminals (pty’s).
 

15)multiple virtual consoles: several independent login sessions through the console, you switch by pressing a hot-key combination (not dependent on video hardware). These are dynamically allocated; you can use up to 64.
 

16)Supports several common filesystems, including minix, Xenix, and all the common system V filesystems, and has an advanced filesystem of it’s own, which offers filesystems of up to 4 TB, and names up to 255 characters long.
 

17)transparent access to MS-DOS partitions (or OS/2 FAT partitions) via a special filesystem: you don’t need any special commands to use the MS-DOS partition, it looks just like a normal Unix filesystem (except for funny restrictions on filenames, permissions, and so on). MS-DOS 6 compressed partitions do not work at this time without a patch (dmsdosfs). VFAT (WNT, Windows 95) support and FAT-32 is available in Linux 2.0
 

18)special filesystem called UMSDOS which allows Linux to be installed on a DOS filesystem.
 

19)read-only HPFS-2 support for OS/2 2.1
 

20)HFS (Macintosh) file system support is available separately as a module.
 

21)CD-ROM filesystem which reads all standard formats of CD-ROMs.
 

22)TCP/IP networking, including ftp, telnet, NFS, etc.
 

23)Lan Manager/Windows Native (SMB) client and server
 

24)Linux is free, in two senses. First, you may pay nothing to obtain and use Linux. On the other hand, you may choose to purchase Linux from a vendor who bundles Linux with special documentation or applications, or who provides technical support. However, even in this case, the cost of Linux is likely to be a fraction of what you’d pay for another operating system. So, Linux is free or nearly free in an economic sense.

Second, and more important, Linux and many Linux applications are distributed in source form. This makes it possible for you and others to modify or improve them. You’re not free to do this with most operating systems, which are distributed in binary form. For example, you can’t make changes to Microsoft Windows or Microsoft Word – only Microsoft can do that. Because of this freedom, Linux is being constantly improved and updated, far outpacing the rate of progress of any other operating system
. For example, Linux will likely be the first operating system to support Intel’s forthcoming Merced 64-bit CPU.

25)Linux has attractive features and performance. Free access to Linux source code let us programmers around the world implement new features, and tweak Linux to improve it’s performance and reliability. The best of these features and tweaks are incorporated in the standard Linux kernel or made available as kernel patches or applications. Not even Microsoft can mobilize and support a software development team as large and dedicated as the volunteer Linux software development team, which numbers in the hundreds of thousands, including programmers, code reviewers, and testers.

Table 1: Sales of Popular Desktop Operating Systems
Operating System
1997
2001 
Windows 95/98
69.4%
65.0%
Windows NT Workstation
9.2
26.2
DOS with Windows 3.x
7.7
0.3
MacOS
4.6
1.9
Linux
2.4
4.2
DOS without Windows
2.3
0.3
Unix
1.0
0.5
OS/2 Warp
0.8
1.2
Other
2.7
0.5

< td class="entry" colspan="1" id="e2qt194" rowspan="1">

1.0
Table 2: The History of Linux
Year
Version
Users
Kernel size (Bytes)
Milestone(s)
1991
0.01
100
63,362
Linus Torvalds writes Linux kernel
1992
0.99
1000
431,591
GNU software integrated with Linux kernel, producing a fully functional operating system
1993
0.99
20,000
937,917
High rate of code contributions prompts Linus to delegate code review responsibility
1994
100,000
1,016,601
First production release
1995
1.2
500,000
1,850,182
Linux adapted to non-Intel processors
1996
2.0
1,500,000
4,718,270
Linux supports multiple processors, IP masquerading, and Java
1999
2.2
7,500,000
10,600,000[4]
Linux growth rate exceeds that of Microsoft Windows NT

Table 3: Popular Linux Distributions and Their Web Home Pages
Distribution
Home Page
Caldera OpenLinux
Debian Linux
Slackware Linux
Red Hat Linux
SuSE. Linux

Table 4: Recommend Linux Web Pages
Web page
URL
Debian Project Web Page
Eric S. Raymond’s Linux Reading List HOWTO
Gary Singleton’s Gary’s Place: Linux News Tips and Links
Joshua Go’s Linux Guide
Linux Documentation Project
Linux Journal Web Page
Linux Journal’s Linux Gazette
Linux Resources
Linux Web Ring
Linux Weekly News
O’Reilly & Associates Linux Center
Renaissoft’s Linux Resources
Robert Kiesling’s Linux Frequently Asked Questions with Answers (FAQ)
Slashdot
Victoria, British Columbia Linux Users Group

Some addtionoal info:

link1: a debat on wether to chose linux or not must read it
http://www.oreilly.com/catalog/debian/chapter/book/ch01_03.html

again some fun time now
http://www.tuxfiles.org/linuxhelp/altview.html

My linux faverate site’s regarding linux
www.google.com/linux
www.linuxhomenetworking.com

Q&A;

1) As i told that linux supports different platforms what are they?
A) Intel X86, Intel Itanium, AMD AMD64 , IBM zSeries, iSeries, pSeries, S/390,notbook systems, and PDA’s etc

2) what is simetric multi processing(SMP)?
A.Symmetrical Multi Processing. A computer hardware architecture which distributes the computing load over a small number of identical processors, which share memory. Very common in Unix and Windows NT/2000 systems.

3)what is pre-emptive multi tasking?
A.
Pre-emption as used with respect to OS means the ability of the operating system to preempt or stop a currently scheduled task in favour of a higher priority task. The scheduling may be one of, but not limited to, Process or I/O scheduling, among others.

4) then my quation is what is non-preemptive multitasking?
A. Any form of multitasking where the OS cannnot preempt a running task and process the next task in the queue(i think now u got the definition)

5)
Why “Free Software” is better than “Open Source”
A. no explination to this from me but i can give a link u can read it
http://www.gnu.org/philosophy/free-software-for-freedom.html

6)what are diffrent file system’s in linux?
A.1).minix 2)nfs, 3)ext, 4)
ext2, 5)ext, 6)vfat, 7)msdos, 8)fat, 9)nls, 10)smbfs, 11)autofs,12)cramfs, 13)nfsd, 14)ufs, 15)ramfs, 16)romfs 

17)autofs4 18)
reiserfs 19) coda 20) ncpfs 21)umsdos 22)sysv 23) udf 24) hfs 25) freevxfs 26) bfs 27) hpfs 28) cmsfs 
29) affs 30)
isofs (i told u linux by default can understand iso files) 31)adfs 32) xfs 33) proc(noting but linux virtual file system) 34) 
xaifs

so now it’s ur duty to check the above file system details in www.google.com

and one more thing the red indicate importat file system’s ok?


7then my quation is what is actually a file systyem?
A.
In computing, a file system is a method for storing and organizing computer files and the data they contain to make it easy to find and access them. File systems may use a storage device such as a hard disk or CD-ROM and involve maintaining the physical location of the files, or they may be virtual and exist only as an access method for virtual data or for data over a network (e.g. NFS)