PCI Express

Ars Technica
Technical overview explaining basic PC system architecture, an explanation of how PCI and PCI-X work, and an outline of the benefits of PCIe, and PCIe to PCI bridging.
http://arstechnica.com/paedia/p/pci-express/pcie-1.html

ASIC Architect
Design and manufacture of PCI Express and DDR I/II controller IP cores. Based in Santa Clara, California.
http://www.asic-architectinc.com

Intel.com
Developer network for PCI Express architecture. Offers overview of the specification, introductory videos, details of books for developers, press releases and how to join the network.
http://developer.intel.com/technology/pciexpress/devnet/

PCI Express Bus Description
A very concise description of PCI Express Bus and its architecture.
http://www.interfacebus.com/Design_Connector_PCI_Express.html

PCI Express Compliance Testing
Gives an overview of the requirements for PCI Express Compliance testing.
http://www.eurekatech.com/products/pci/pcie_compliance.htm

PCI-SIG
Standards development group. Offers details of technology specifications, document review and compliance testing, test software and checklists and press releases.
http://www.pcisig.com/specifications/pciexpress/

PCMCIA: ExpressCard
Standard for higher speed PCMCIA form factor cards that supports USB2 and PCI Express. Includes FAQ and technical information.
http://www.expresscard.org/web/site/

Wikipedia
Article outlining the components of the protocol and competing formats.
http://en.wikipedia.org/wiki/PCI-Express

PCI Express Design: A Lesson In Techno-Shock
Explains in detail the challenges associated with implementation of PCI Express bus. Also looks at the rewards of going through with the implementation. <small>(April 28, 2005)</small>
http://www.elecdesign.com/Articles/Index.cfm?ArticleID=10174

Neoseeker.com
Article including a technology overview, comparison with older buses and considerations of its future prospects. <small>(April 21, 2004)</small>
http://www.neoseeker.com/Articles/Hardware/Features/pciexpresstech/

Tom's Hardware Guide
Article discussing the impact of PCI Express on the graphics and gaming market, its relative performance compared to AGP, and the responses of the two main graphic cards manufacturers to its introduction. <small>(March 10, 2004)</small>
http://tomshardware.co.uk/2004/03/10/future_promise_for_graphics/index.html

AnandTech
Article covering history of the bus market and an explanation of how the specification works. <small>(December 6, 2003)</small>
http://www.anandtech.com/showdoc.aspx?i=1830