Differences with Linux and Windows

Even though OpenSolaris is free and open source similar to Linux, it is different in many ways. Unlike the Linux distributions such as Ubuntu, Fedora and OpenSUSE, which are based on the Linux kernel, OpenSolaris is based on the Solaris kernel. This makes OpenSolaris fundamentally different from all the Linux based operating systems.

But both OpenSolaris and Linux (and many other Unix like operating systems) are POSIX compliant (which is an industry standard for Unix based OS) and so thousands of applications which run on Linux based operating systems, also run on OpenSolaris. Moreover, OpenSolaris has many unique features, which are not available on any flavour of Linux. For example, while Linux uses Ext3 or Ext4 file systems, OpenSolaris uses the ZFS file system which is a much more advanced file system. We will discuss ZFS in greater detail later in the book.

OpenSolaris also provides developer tools like DTrace, which allow programmers and system administrators to probe the inner functioning of an applications while it is still running. DTrace will be covered in details as well. Differences between Linux and OpenSolaris exists in licensing as well.

While Linux is released under the GNU Public License (GPL), OpenSolaris is released under Common Development and Distribution License (CDDL). CDDL is based on Mozilla Public License (MPL) and unlike GPL, which is a project based license, CDDL is a file based license. This allows users and developers a greater level of freedom and permits both closed source as well as open source components to co-exist in the same project.

OpenSolaris is very different from the operating systems of the Microsoft Windows family. As stated earlier, unlike Windows, OpenSolaris is free and open source. Even though it is possible to run some of the applications developed for Windows using WINE, OpenSolaris and Windows are different in most of the technological aspects.

Getting familiar

Like every other popular operating system, OpenSolaris has a GUI, which is based on GNOME. Thousands of applications, including the most popular open source applications Firefox, OpenOffice and Thunderbird have been ported to OpenSolaris. OpenSolaris is distributed under the Common Development and Distribution License (CDDL), which is a
variant of the Mozilla licence used by Firefox. Because many applications, including the GNOME desktop environment, are common with various Linux distributions, you can confuse OpenSolaris to be yet another Linux distribution. However, OpenSolaris is not Linux! There are many unique features available on OpenSolaris that sets it apart from all the other operating systems such as Linux and Windows.

The term OpenSolaris can also have other meanings to depending on the context it is used. OpenSolaris is used to refer to:

• An operating system code base that is originally based on Sun's proprietary Solaris operating system.
• An open source development project.
• The community of users and developers who contribute to the project OpenSolaris.
• A free binary distribution.
  

Throughout this book, we'll be referring to the last meaning in the list, the term OpenSolaris means a free binary distribution of the OpenSolaris software that is available for redistribution under the terms of the Common Development and Distribution License (CDDL), unless otherwise stated.

Getting started

OpenSolaris is the binary distribution of a mature, free and open source operating system, based around Sun Microsystems' Solaris operating system. The history of OpenSolaris begins in 1983 (27 years ago!) when Sun released its own flavour of Unix named SunOS 1.0. In June 1992, SunOS was renamed Solaris.

With millions of installations all around the globe, Solaris is one of the most popular flavours of Unix in the world and is known for its scalability, security and stability. In 2005, Sun decided to open source the code base of Solaris and as the result of it, OpenSolaris was born. OpenSolaris is available for the x86 platform as well as the SPARC platform. Both 32-bit and 64-bit versions are available and can be downloaded from http://www.opensolaris.com.