WxFormBuilder

wxFormBuilder is an application that can literally speed up GUI development, being Python either C++ the programming language of your choice.

To install it, you need to first add the gentoo-zh overlay:

root # layman -a gentoo-zh

Then, since premake 3.7 is currently an ebuild prerequisite, though the core system is already providing premake 4, you have to directly specify it:

root # emerge =dev-util/premake-3.7

You may now proceed and install wxFormBuilder itself:

root # emerge dev-util/wxformbuilder

Official Documentation

See http://wxformbuilder.org