There is no need for, as there is UNIX!
:-) Dirk
Operating systems are being created and improved constantly, so there is not, and will hopefully never be, a "last" operating system.
An operating system is just like any other piece of software: none is perfect. Because of this, many attempts are being made to create the "best" one available.
It is not hard to load operating systems software but first you must make sure the old operating system has been removed then use the software discs you have to being loading the new system.
The operating systems which were developed by Apple and IBM are Mac OS and OS/2. However, OS/2 is no longer being used as IBM is no longer in the operating system market. Microsoft now makes operating systems which work on IBM computers.
XHTML support is based on the browser being run, not the underlying operating system. Any operating system capable of running a modern browser can thus use XHTML. There are dozens of systems that would meet this definition.
Touch screen PCs are the future of technology. Using mobile technology, without being tethered to a desk is a great thing. The Android and Windows 8 operating systems were created specifically for tough screen PCs.
Almost every operating system that was ever created is still being used at least occasionally by someone.
Unix and any Unix based operating systems can be downloaded for free. There are also many operating systems that can run on top of Windows or side by side. Many of these types of operating systems are Lynix based. All of these operating systems are "open source" which means that any one that knows how to, they can modify, rewrite, or add new features to the programs. Being open source software is that makes it free to download.
They defended their Internet browsers being installed with their operating systems by pointing out that the browser could not be sold separately.
Dynamic disk
Despite being created by different software developers, most operating systems today are graphical-interface-oriented. Also, most of the OS's, including three of the most popular (Windows, Macintosh and Linux) support multitasking.
The Camino browser runs on OS X operating system. However in May 2013, the Camino organization announced that the bowser is not being developed anymore.