Why is multiple inheritance not supported in most of programming language?

Question

Why is multiple inheritance not supported in most of programming language?

I could really use this feature to develop different layout of application?

Answer 1

One reason not to support it is ambiguity of method resolution.

http://en.wikipedia.org/wiki/Diamond_problem

However, I'm not sure what you mean by "most" programming languages. Many that are in use today support it directly (C++, Python, Perl, OCaml) or have a mechanism for similar functionality (Ruby and Scala come to mind).