Why Linux?

Linux is booming every where and we hear Linux every where.Many of you would like to know what makes Linux so special.Why not discuss " Why Linux?" or must say "What makes Linux best choice?" In short advantages of Linux are mentioned in this blog. One of the best method to know what makes Linux special is to use it yourself,explore it and feel the experience.So try Linux and you will never look back to any other OS, I am sure. From my personal experience I would explain the advantages of Linux:

• Linux is open source.With open source end user has the flexibility to modify Linux's source code. In short the user has freedom  to modify source code which in turn imparts more power to the end user.
• Linux is network friendly as the network of servers,clients and  workstations can easily be setup. Linux facilitates sharing of network,cpu,modem and other such devices very easily.
• Linux is almost free and is a low cost OS as most of the compilers,document viewers,browsers and other such applications come free with the OS. End user doesn't have to gain software licences as much of its software come with the GNU General Public License.
• You can very well customize the Linux kernel to suit your needs.You can even make Linux as small as 1.4 Mb which can fit on even floppy drive.
• Linux is very Reliable and Backwards-Compatible
• Linux being open source,open source communities fix the security  vulnerabilities very fast.
• Linux is almost free form viruses, worms, spy-ware, and other kinds of malware plagues.You don't need to get the Anti-virus Licences.
• Linux and other Unix-like operating systems are well protected and are designed to be secure.
•  Linux provides high performance on workstations and on networks and can  it handle unusually large numbers of users simultaneously. 
• Linux is stable as it doesn't need to be rebooted periodically and doesn’t freeze up or slow down over time due to memory leaks.
• Linux has excellent X windows System which is very flexible.
• Linux is Multitasking.
• Linux supports almost all the platforms like x86, AMD64, Intel® 64 and Itanium.
• Linux has good community support in the form of forums,blogs etc.
• Some Linux flavours like Ubuntu  gets updated automatically with latest bug patches, security patches automatically. 

Linux Distributions

Many people are curious about various Linux Distributions available.Some of the widely used Linux Distributions available in market are given below.Its worth reading about Red Hat distributions, enterprise and open source versions both.

• Fedora http://fedoraproject.org/
• CentOS http://www.centos.org/
• Scientific Linux  https://www.scientificlinux.org/
• Ubuntu http://www.ubuntu.com/
• openSUSE http://www.opensuse.org/en/
• Debian http://www.debian.org/
• Mandriva http://www2.mandriva.com/
• Linux Mint http://linuxmint.com/
• PCLinuxOS http://www.pclinuxos.com/
• Slackware http://www.slackware.com/
• Gentoo Linux http://www.gentoo.org/
• FreeBSD http://www.freebsd.org/
• openSolaris http://www.opensolaris.com/

Also vist http://www.distrowatch.com  for information on several hundred distributions

DistroWatch is a website which provides news, popularity rankings, and other general information about various Linux distributions 

RedHat Linux,Fedora,RHEL and Centos

• Red Hat Linux

Red Hat Linux, assembled by the company Red Hat, was a popular Linux based operating system until its discontinuation in 2004 Red Hat Linux 1.0 was released on November 3, 1994. It was originally called "Red Hat Commercial Linux Red launched various other version like 2.0 3.0...8.0 and Red Hat Linux 9, the final release, hit its official end-of-life on 2004-04-30. Since 2003, Red Hat has discontinued the Red Hat Linux line in favour of Red Hat Enterprise Linux (RHEL) for enterprise environments.

• Fedora

Fedora, developed by the community-supported Fedora Project and sponsored by Red Hat, is the free version best suited for home use. Red Hat Linux 9,the final release, hit its official end-of-life on 2004-04-30, although updates were published for it through 2006 by the Fedora Legacy project until that shut down in early 2007.

Fedora Releases

• Fedora Core 1–4
• Fedora Core 5–6
• Fedora 7
• Fedora 8
• Fedora 9
• Fedora 10
• Fedora 11
• Fedora 12
• Fedora 13

Fedora Core v/s Fedora 

Starting with Fedora 7, there is no more Core, and no more Extras; there is only Fedora.That is the biggest difference between Fedora Core 6 and Fedora 7 was the merging of the Red Hat "Core" and Community "Extras" repositories,and the new build system put in place to manage those packages.This release used entirely new build and compose tools that enabled the user to create fully-customized Fedora distributions that could also include packages from any third party provider.

• CentOS

CentOS(Community ENTerprise Operating System) is a community-supported, mainly free software operating system based on Red Hat Enterprise Linux. It exists to provide a free enterprise class computing platform.CentOS developers use Red Hat's source code to create a final product very similar to Red Hat Enterprise Linux. Red Hat's branding and logos are changed because Red Hat does not allow them to be redistributed.CentOS is available free of charge. CentOS provides Technical Support through official mailing lists, web forums, and chat rooms. 

•  Scientific Linux 

SL is a Linux release put together by Fermilab,CERN and various other labs and universities around the world. Its primary purpose is to reduce duplicated effort of the labs, and to have a common install base for the various experimenters.This product is derived from the free &  open source software made available by Red Hat Inc., but is not produced, maintained or supported by Red Hat. Specifically, this product is built from the source code for Red Hat Enterprise Linux versions, under the terms and conditions of Red Hat Enterprise Linux's EULA and the GNU GPL.

The base SL distribution is basically Enterprise Linux, recompiled from source.Main goal for the base distribution is to have everything compatible with Enterprise, with only a few minor additions or changes.It allows easy customization for a site, without disturbing the Scientific Linux base. The various labs are able to add their own modifications to their own site areas. By the magic of scripts, and the anaconda installer, each site is to be able to create their own distributions with minimal effort. Or, if a users wishes, they can simply install the base SL release.

Various Linux Certifications

Certification in Today's world is a must.It sets you apart form all others. Certified IT pros have a  advantage over their colleagues. While holding a current IT accreditation is no guarantee against being laid off, the more education, expertise, and skills you can demonstrate, the better. Certification qualifies employees for higher pay grades.In cases where two otherwise equal candidates are competing for the same lucrative job offer, one applicant’s certifications could prove the deciding factor.

Various Linux certifications available in market are:

1. RedHat
Red Hat Certified Engineer  (RHCE)

Red Hat Certified Security Specialist (RHCSS)

Red Hat Certified Virtualization Administrator (RHCVA)

Red Hat Certified System Administrator (RHCSA)

Red Hat Certified Datacenter Specialist (RHCDS)

Red Hat Certified Architect (RHCA)

2. CompTIA

Linux+

3. Linux Professional Institute 

LPIC-101

LPIC-102

LPIC-103

4. Novell

Novell Certified Linux Professional 11
Novel Certified Linux Administrator

6. Ubuntu 

Ubuntu Certified Professional (UCP)

My personal choice is LPIC and RHCE.

But please note that All the Red Hat Certifications are Performance based and needs rigorous training and practice.So until and unless you practice  much and  get hands on Linux dont go for Red Hat certifications.