Given its sheer size, this summarises what I have read rather than a definitive guide to the report.  

Government

It has been made clear that the government was well aware of the cladding risks prior to Grenfell when there were previous fire events but failed to act. Instead, they simply pushed ahead, ignored safety issues, and stuck with their deregulatory agenda.

Product Manufacturers

This is where it hurts. There was systematic incompetence, dishonesty, and even deliberate manipulation and misrepresentation in testing processes—lies after lies after lies.

Key manufacturers mentioned were 

1. Kingspan
2. Celotex
3. Arconic
4. Siderise

Others were to blame

BRE - The Building Research Establishment received more damnation than most.  In short, they were a trusted construction industry company responsible for fire safety and testing in accordance with British Standard 8414.  Unprofessional conduct and inadequate is how the reports find them.  Oversight and rigour were lacking, which enabled manufacturers to lie and manipulate test results.  My understanding at this point is that at least one test was useless.

Four industry bodies, NHBC, BBA, UKAS, and LABC, failed to ensure the accuracy of statements made on certificates. 

Landlords are accused of indifference to fire safety.

Contractors were seen as incompetent and dishonest.

Fire and Police services are accused of failing to learn from previous events, again poor leadership and ineffective.

From the bottom to the top, it's lies, incompetence, dishonesty and, as always, profit-driven!

There have, of course, been recommendations.

What are the recommendations?

These are the key ones.

1. A new single independent body to act as regulator.
2. A new Doc B is to be reviewed; this is a fire safety document relating to buildings.
3. Development of a new test method to assess building materials.
4. New fire strategy for buildings.
5. Fire Risk Assessors must have mandatory accreditation.
6. Architect training and they will have to make a statement on fire safety/compliance.
7. A new fire safety engineer profession with a regulated body to develop training and set standards.
8. Establishment of a building control panel.
9. College of Fire and Rescue to be created.

There is more, but you get the idea, so rip it all up and start again.

Honestly, I was expecting the report to raise all sorts of failings, but I didn't expect it to be as bad as this—truly, sickening and saddening.  

Unfortunately, it will take more years to bring those responsible to court if it ever happens.