Which is the OFFICIAL HM Land Registry?

When i search online I can see there are a number of sponsored sites offering land registry information 
Are these all the same organisation or are they different to the HM Land Registry which provides this support forum for example?

Have a read of our blogs on the subject 
The most recent is Avoid paying more than you need to for HM Land Registry information – HM Land Registry
And you may find this older one of interest too - Will the real land registry please stand up? – HM Land Registry