Custom on UI for interface

How to make custom UI in Blender as look like Softimage for example ?

Where i can access in source code?

Many thanks.

There is no fast way to make Blender’s UI look like another software, it’s would require changes all over the source code and experience programming in C and Python.

Here is a high level overview of the code layout:

I understood and thank you for your help. I have question about icon, how they are to manage for all icon, UI looking in Blender with hand to code ?

There is information about icons in Blender here:

Thank you for about add icons