After looking over the list of organizations and the summaries of each it should be apparent why they are referred to as Alphabet Organizations.  They all serve a purpose, to provide an organized set of rules standards, and insurance policies for kart racing events.  They don't all work the same way, nor are their rules all identical.

International Karting Federation - IKF

The stories told is that IKF first began as a dis-organized group of weekend parking lot warriors in the 1950's that became organized and founded the IKF in Los Angeles.  IKF swept across the USA but having west coast roots had a perceived negligence of the eastern half of the karters in the USA.  IKF was run more like a club then a business.  That concept actually worked well in many ways, but in some ways worked against them.

IKF followed the idea that karting should be a very family-oriented sport, and still follows that philosophy today.  They fell way behind the times with promoting their own products and are now being swallowed by the WKA.

IKF is the predominant organization to the west of the Rocky Mountain chain.  LA is considered a crown jewel for a karting organization as it has the highest density of tracks and shops in the country.

World Karting Association - WKA

This organization formed in the early 70's as a result of eastern dissatisfaction with the IKF.  Having most of their focus in the east, WKA enjoyed significant growth with the passion the easterners had with oval racing.  Originally formed out of Xenia Ohio, in the late 80's WKA was bought out by a NASCAR magnate Humpy Wheeler, and moved to Concorde NC. 

WKA actually operated as a business with a profit motive.  Like IKF, WKA maintained a position of friendliness to the family-oriented sport concept, while trying to form some cooperative efforts to the European suppliers to karting.

WKA has dabbled with hosting a Pro Series a couple of times but never really had the steam to make it permanent.

Until recently, the WKA never made many inroads west of the Mississippi.  Early in 2004 WKA planned a series of races in the LA area, and has had significant success in the early going.

CIK (Europe)

This is a European organization more one to create standards then anything else.  European race promoters pay the CIK to provide these standards as do the product manufacturers.  This gives almost all of Europe the advantage of a single set of unified rules around which they have built a huge manufacturing and supply industry.  To give you an example of how valuable this is; In the US we have one manufacturer that builds motors - Briggs & Stratton - and that's derived from a motor with a different application.  In Europe there are about a dozen manufacturers of purpose built kart motors.  Same for chassis and bodywork which is why there are so many references to CIK.  They are the Underwriters Laboratories of Karting.

Karters of America Racing Triad - KART

Now there is an appropriate acronym.  KART began as one person's disappointment with IKF and serves the area between the Mississippi and the Rocky Mountains.  More of an IKF clone that serves a division of the US that no one seemed to want.

Super Karts USA - SKUSA

In the early 90's when the rage to bolt a dirt bike motor on a kart first began to be popular there was little to no support from the the existing Orgs to see this happen.  SKUSA formed with a mission to take karting to the next level and with lots of hard work became a premier organization by 2000.  Using the web as a media and freely offering their rulebook for anyone to download, they became the standards organization on which shifter karter was based.  IKF and WKA followed the SKUSA leadership for a few years.

Today SKUSA operates a regional and national venue and continues to set the Moto based standards as well as the standards of Pro level event excellence.  SKUSA has evolved into too many variations of shifters and picked up on the growing TAG classes as part of it's core.

Stars

In conjunction with SKUSA, Brian Herta developed the Stars of Tomorrow series.  This later led to creating a totally new organization with a common mission with a twist - focusing on brining over CIK classes of ICA and ICC.  Recently Stars added the Easykart a type of TAG class to the lineup.  While Stars has no regional core, they have worked a cooperative agreement to have WKA serve as their regional draw.  Stars is evolving into a Pro organization much like SKUSA.

X-Karts

Created by the same person who launched the original X-Games, X-Karts is another entry into the National-Pro scene.  X-Karts differs from most other national/Pro organizations in having a background with growing public visibility of up & coming sports through corporate sponsorship and televised broadcasts.  They are not specifically a karting organization, they are a sports promotional organization that are currently trying to bring karting into the public view.

Rotax SSC

Rotax has the distinction of being both manufacturer and organizer of the only real world championship series.  Over 30 countries are represented each having a national championship race, with the world championship culminating in a different country every year.  The Rotax importer to the US is SSC who also manages the US Rotax Nationals, and negotiates the qualification process for participants with nearly all other US racing organizations.

TAGUSA

TAG stands for "Touch And Go" and was created to provide a single class for a new generation of motors coming to the US from Europe.  As the Europeans had developed ultra high performance 100cc machines producing over 25 HP and turning up to 19,000 RPM, the quest for a simple and more cost effective package was realized by increasing volume to 125cc and reducing RPM.  Adding an on-board starter and low stall speed clutch made the package very friendly to entry level karters, yet provided the level of power modern chassis are capable of.  The TAG concept was first introduced to the US by Kartweb in late 2001 thorough the publishing of technical standards that were basically full rules package that were freely available to anyone who wanted to use them. 

At the beginning of 2003, TCM Racing formed a new organization TAGUSA specifically to promote their own series of TAG Racing.  Tragically the founder of TAGUSA Tom Argy Jr passed away in November of 2003, and through the body of the TAGUSA directors and contributors TAGUSA was reborn.  The new TAGUSA returned to the original charter set forth by Kartweb to act as a standards committee with the intent of maintaining a single set of rules and uniformity among the grassroots, regional and national organizations.

As you can see, these are the major players in the Alphabet Soup.  Not all their rules are the same, and not all hold regionals in the same area.  What's interesting is that the number of organizations have grown from 3 to 8 in the last 5 years, yet the number of active karters has actually decreased.  The growth of the number of organizations has significantly stifled the growth of the sport at the entry level.