If you are familiar with CakePHP 2/3 then you should take a look to CakePHP 4. I used this Framework since 10 years and I’m still using it till now on my web apps projects.
CakePHP 4 is coming with breaking changes. My last project I made it using CakePHP 3.6. I found a lot of API functions that Intellij warnings me that they will be removed on 4.0.
This new release is targeting newest versions of PHP specially 7.2 with it typehinting specification.
And finally, the FormHelper now generates HTML5 validation messages and datetime inputs.
Personally, It’s not a big change between 3.7 and 4.0 in file structures and classes naming comparing to the biggest breaking change between CakePHP 2.6 and CakePHP 3.0