Where do they get their codenames?
Technology companies have become very, very fond of codenames. They have become a marketing tool, and often show up quite a bit in the trade press months (even years) before a product release. While we can't hope to cover every codename system in use, we can take a look at some of the better-known ones.
Advanced Micro Devices (AMD)
AMD has gone through several phases in its choices of codenames. When it first began designing its own microprocessors, it started with very straightforward names. The Am5x86 effectively had no codename, and its name was simply a compact description of what the product was (AMD 5th generation x86 processor). It was followed by the K5 series, with similarly uninspiring codenames (like 5k86).
With the K6, they began to get more creative. The K6 family took codenames from the names of characters in the Land Before Time children's movie series (Little Foot, Chomper, Sharptooth). The possibly-apocryphal story goes that this was the suggestion of an AMD engineer's child.
For the Athlon family, AMD called on the names of a variety of cars; the British Argon make, Ford Orion, Ford Thunderbird, Triumph Spitfire, and Chevrolet Corvette. For the follow-on Athlon XP and MP family, they switched to horses and things related to horses. And so we had chips named after various breeds and kinds of horses (Palomino, Thoroughbred, Morgan) as well as individual horses (Sir Barton, Applebred).
For the Athlon 64 and Opteron family, which are built on the microarchitecture known as either K8 or Hammer, AMD briefly used types of hammers as codenames (Clawhammer, Sledgehammer).
Apparently realizing that there are only so many types of hammers with which the average person is familiar, they immediately changed course. Borrowing a concept from Intel, they began using the names of cities across the world. They used quite a large number of names in very little time: Newcastle, San Diego, Georgetown, Lancaster, Paris, Brisbane, and many more. Dual-core Opterons briefly flirted with using country names instead (Denmark, Egypt), then reverted back (Santa Rosa, Santa Anna, Barcelona).
Through all of this they have also been developing their various "platforms", combinations of a processor and other components, which have usually been named for very mundane objects (Spider, Kite).
AMD's most recent product family is the Phenom, and once again they have a new source of codenames. AMD marketing literature has sometimes refered to these as the Stars family, because they are named for stars. The first out of the gate have been Agena (another name for Beta Centauri) and Toliman (another name for Alpha Centauri).
If you are lost in this soup, then of course 10stripe can dissect AMD's codenames for you.
We can even map many AMD codenames out for you, though of course it is difficult to map a horse.
Apple
As a seller of both hardware and software, Apple has ample opportunity to come up with lots and lots of codenames, and they have never shied away from doing so. In fact, many Apple hardware products have held multiple, simultaneous codenames, often one for internal use and one for external use. Originally these were female names, typically the name of one of the engineers' daughter. Then came different types of apples, pop culture references, and all sorts of things. This is more than we could comfortably describe in this space, but others have examined Apple's codenames before us.
Apple's recent software products have used more sane, and better-publicized, codenames than many of their predecessors. Each iteration of the OS X operating system is named for a big cat (Panther, Cheetah, Leopard, etc.). The APIs that applications use to talk to the operating system (the "glue" that makes things work together) are named after substances (Carbon, Cocoa).
Canonical
Canonical is the company behind Ubuntu, a Linux distribution based on Debian. Ubuntu's first version codename (Warty Warthog) was more commentary than codename, hinting at the rough edges that had yet to be addressed. The use of an alliterative adjective-animal name pair stuck; all versions since have followed that convention. After a few versions, the developers settled on an alphabetical progressions, beginning at Dapper Drake and so far reaching Intrepid Ibex. The names generally use an adjective that is meant to reflect strength or some other positive trait.
Debian
Not entirely unlike AMD, the Debian GNU/Linux operating system takes all of its codenames from the children's movie Toy Story. Each version of Debian is named after some character from the movie. The names are used in no particular order.
Most of the names track along with a specific version, so woody would initially refer to the "testing" version, but would later refer to the "stable" version (3.0, specifically). The exception is sid. The name sid always refers to the current "unstable" version, the one subject to the most radical change and the highest odds of breaking something. This is appropriate enough as Sid was a rather unstable character and, as the Debian FAQ put it, he "was the boy next door who destroyed toys :-)".
Intel
Intel's microprocessor, chipset, and other products have long used geographic codenames. These are often cities (Tulsa, Conroe), rivers (Klamath), or mountains/mountain ranges (Cascades, Mount Bonnell). It is often stated that Intel has engineers on the project submit a list of geographic locations as possible codenames, which are then run by marketing (to ensure the names look nice on a PowerPoint slide) and legal (to ensure there are no trademark issues, one of the advantages of geographic codenames).
Typically a product's namesake will be near the Intel facility where the product was designed (at least in part). For some time this meant that the codenames were focused in the Pacific Northwest. More recently, as Intel has distributed design work more, the names have become more diverse. And so we have the Core Duo Dothan (an ancient city in Israel, for a chip designed in Israel) and Core 2 Duo Conroe (a city in Texas not too far from the Austin facility where the chip was designed).
As with AMD, 10stripe has already delved into Intel's various codenames. And for those that are named after a place, we can map Intel's codenames as well.
Microsoft
Like Intel, Microsoft has always favored geographic codenames for its operating systems and other software products. Several versions of Windows have used city names as their codenames (Chicago, Memphis, Whistler), while one (Windows 2000) never even had a codename. Other products sometimes follow a particular convention (most versions of Exchange server have been named for one of the transition metals like Platinum or Titanium), and sometimes bear no obvious pattern (the Xbox 360's Xenon processor and Falcon motherboard).
VIA
VIA is an oddball in this list because most of its processors have two codenames. This is not as odd as it might sound, though it is fairly odd. VIA is a Taiwanese company, but their processors are all designed by Centaur, a Texas-based company that they acquired several years ago. The Texan engineers use Biblical codenames (such as Mark, Luke, and Esther), while their Taiwanese bosses use much less creative names (such as C5XL, C5C, and C5P).
We have previously taken a look at VIA's processors, with much more to come.