Well,

I am new to linux world, can anybody please tell me what are diff. between Redhat 9.0 & Redhat 4.0 enterprose version.Are thay belong to same org. of different one ?

Thanx

Redhat 9.0 is old and unsupported. Redhat 4.0 enterprise is a non-free (as in beer) product meant mostly for businesses or other customers who want support from Redhat. For a free as in beer redhat version then have a look at Fedora core, which is what the free redhat turned into a while back.

Redhat 9 was the last regular redhat boxed product before Redhat forked off Fedora Core. The RH enterprise edition is Redhat's commercial offering, aimed at enterprise customers, while Fedora Core is a user supported product you can download.

Actually, Redhat 9 is still supported through the Fedora Legacy project. See http://www.fedoralegacy.org/updates/RH9/

Redhat Enterprise Linux (RHEL) 4 is Redhat's commercial offering that's generally targeted toward the server market, though is also often used on Corporate desktops. While the distribution itself is free (as in speech), you have to buy a subscription to obtain the binary pre-built system. You can get the source RPMs for completely free, however, and use/redistrubute them as they're licensed under the GPL (minus some of the artwork and Redhat trademarks). Enter CentOS/Whitebox Linux/Tao Linux/Piebox Linux/etc.

All of the aforementioned distributions are really just Redhat Enterprise Linux that's had the non-free Redhat trademarks and artwork removed, but apart from that they're the exact same thing that you'd get if you spent the $349-$2499 on the Redhat subscription (minus the official Redhat support and Redhat Network of course). So, if you're wanting to use or play around with RHEL, just visit one of those project's websites and download away. If you're wondering which one to choose, I'd highly recommend CentOS as it has a very active community and they're extremely good about getting patches out in a timely fashion. You can check out their website at http://www.centos.org/

Hope that helps!

Moved: This thread is more suitable in Red Hat and has been moved accordingly to help your thread/question get the exposure it deserves.

Good post Gato Azul, some minor comments:

Red Hat Enterprise Linux Workstation is clearly geared towards professional desktop and development use. Red Hat is pushing new technologies in this area too (for instance, the Java toolchain, Systemtap, and Frysk).

Subscriptions actually start at $179 for a RHEL Workstation subscription. A pretty fair price IMO, what many people used to spend on two Red Hat or SUSE boxes a year. And the price competes well with Windows offerings. Of course, it should be said that subscribers are primarily paying for a service.

CentOS is indeed a good place to start if you want to test the waters .