Datasheet

12 Part I: Getting Started in Red Hat Linux
NOTE: Red Hat now offers an economical service for getting critical updates and patches to Red Hat Linux
that I strongly recommend to anyone whose system is always up on the Internet. For $60 a year, you get
security e-mail alerts and the ability to do quick downloads and install patches. (See Chapter 10 for details.)
New Features in Red Hat Linux 9
With Red Hat Linux 9, Red Hat is sending clear messages about the direction it is taking its
operating system. A glance at the desktop will tell you that it is undeniably a Red Hat Linux
system. Instead of offering multiple, low-quality versions of every service, Red Hat is backing
select services, then integrating, testing, and supporting them well. New on the inside of Red
Hat Linux is the Native POSIX Threads Library (see the "What Is NPTL?" sidebar).
What Is NPTL?
Although you don't see it, the Native POSIX Thread Library is the most significant
addition to Red Hat Linux 9 (and the main reason why the release is called 9 instead
of 8.1). Threads are a way of allowing small pieces of code to run independently,
without incurring the overhead it takes to start and stop an entire process.
As Ulrich Drepper said, the thread library is "…a very thin layer on top of the kernel.
This helps to achieve a maximum of performance for a minimal price." (See
http://kerneltrap.org/node.php?id=422) What does this mean to you? It could
mean a few things:
• Applications that use NPTL could run much faster.
• Applications that use an older way of implementing threads might be broken at
first.
The rule of thumb regarding when a release goes to a major number (such as Red Hat
Linux 8 or 9, as opposed to 7.2 or 7.3) is that the release will break a significant
number of applications. Some applications intended for Red Hat Linux 8 may require
that code be rewritten or recompiled to run on Red Hat Linux 9.
While Red Hat Linux 9 does not provide many new major features, it is a great product to
choose if you are going to bet your business on an operating system. Inside Red Hat Linux 9
are solid versions of components you need in a high-quality desktop or server system. Here is
a list of major components in Red Hat Linux 9 (with version numbers):
• Linux kernel: version 2.4.20
• GNOME (desktop environment): version 2.2
• KDE (desktop environment): version 3.1
• GCC (GNU C language compilation system): version 3.2.2
• Apache (Web server): version 2.0.40