Just noticed this in the linux's kernel code main.c:
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright 2007 rPath, Inc. - All Rights Reserved
* Copyright 2009 Intel Corporation; author H. Peter Anvin
How do they apply to the kernel? It seems really strange to me, also because the next line is:
* This file is part of the Linux kernel, and is made available under
* the terms of the GNU General Public License version 2.
Copyright and open source are not mutually exclusive. In fact, most open-source licenses depend on copyright in order to function properly. The GPL comes most readily to mind: you couldn't enforce the requirement to share-alike if copyright didn't let the author decide who may or may not copy the work. But even something as simple as an MIT-style attribution requirement couldn't be enforced without copyright. The Creative Commons licenses also depend on copyright.
Non-copyrighted software does exist (in some jurisdictions). Such software is often said to be in the public domain, and although it is usually classified alongside open-source, it works quite differently: instead of using a license to explicitly allow the sharing of software, it doesn't use a license at all. That's why Creative Commons calls CC0 a dedication instead of a license (though it includes a license for jurisdictions that do not recognize the public domain). SQLite is a famous example of public-domain software, though it does not use CC0.
The "All rights reserved" by rPath is a bit strange to see in an open-source product, but it is probably just standard boilerplate. The GPL renders it pretty much moot anyway; the rights are reserved, but then the GPL explicitly re-grants the rights that make the software open-source.
It's exactly what it says on the tin.
Free and open source software is software that the copyright owners license to you (or anyone else) under a free license (that meets the Open Software Initiative (OSI) or Free Software Foundation (FSF) definition of open source or free software)
The copyright is owned by Linus, rPath and Intel (and possibly others). They have licensed this to you under the GPLv2, which is a free software license. The GPLv2 is a license that grants you the rights to use it, and guarantees that it remains free and open source software.
The phrase "all rights reserved" simply indicates the person or entity holds the copyright, it has nothing to do with any licensing on the product.
The Linux kernel is a composite work by multiple entities. The three listed entities share the copyright of the file together and have agreed to license it to each other (and to you) under GNU GPLv2.
Having all authors keep their copyright is a common strategy in the Open Source community to prevent works from becomming un-free in the future. It makes it impossible for one copyright holder to change the license without approval of the others. For a work like the Linux kernel which has literally thousands of contributors by now, this is practically impossible.
