It's better known as just I.P.A in Uk. It is the main tour of those pros and players who play to "World Rules" (strange title as parts of each of Uk, Australia, France, Ireland and South Africa are just about the only places who play them). Another closely related "World Rules" website is
www.epa.org.uk
The other main rule code is "Blackball Rules" and the related website is
www.eba-pool.com. They also have their own main tour for pros and others.
The two controlling bodies are perpetually at odds with each other.
The main website forums etc for players of Uk style 8 ball of all codes is
www.uk8ball.com
It is generally played on 7 ft tables though occasionally 8 ft tables are used in the latter televised stages of "World Championships" due the larger size being more tv screen friendly.The pockets are tighter than USA style tables in respect of ball/pocket size ratio and the cut of the corner pocket jaws also makes potting more difficult.
IPT (and other USA style pool) participants such as for example Darren Appleton, Mick Hill, Karl Boyes, Yannick Beaufils, Brian Saleh, Jayson Shaw, Pat Holtz and Ben Davies were all weaned on this type of 8 ball and most still play it regularly.
Snooker World Championship finalist Mark Selby was last years World Rules Uk 8 Ball World Champion, but lost in the quarters this year.