Graying out texts with/without lines with LaTeX?

Question

This is a screen capture from Pragmatic Bookshelf.

How to make this boxed text with LaTeX? It has it\'s own heading with underline, and uses color.

And

Answer 1

The rounded box is most easily created using TikZ:

\begin{tikzpicture}
  \draw node[draw=black,fill=black!20,rounded corners,inner sep=2ex,text width=\textwidth] {
    Lorem ipsum dolor sit amet \dots
    };
\end{tikzpicture}