What's the rationale behind the Qt way of naming classes?

Question

I am wondering why Qt uses Q before every class name rather than putting everything in a namespace. Is there any particular reason, such as making the names easy to search for, or is it just about brand names?

Answer 1

I believe it is historical. Namespaces were introduced into C++ around 1995. Qt development started in 1991 so namespaces could not be used, obviously.