[Tex/LaTex] Fancy Chapter Headings

chapterssectioning

I'm reading a document created with TeX, and it has rather nice chapter headings. Does anyone know how this was done?
Fancy Chapter Headings

Update

Ok, I've got quite far using TikZ, the only thing I haven't got is the number extending into the margin:

\usepackage{titlesec}
\usepackage{tikz}
\usetikzlibrary{calc} 

\titleformat{\chapter}[display]
{}
{\hfill \tikz[remember picture] \node[] (nr) {\fontsize{20}{70}\selectfont\color{black}\textsc{Chapter~~} \fontsize{60}{70}\selectfont\color{black}\thechapter};
\begin{tikzpicture}[overlay,remember picture]
\coordinate (rightborder) at ($(nr)+(100,0)$);
\coordinate (right) at ($(nr.east) + (0.5,0)$);
\draw[line width=4.5em] (right) -- (rightborder);
\end{tikzpicture}}
{-1ex}
{\filleft\fontsize{30}{50}\selectfont}
[\vspace{-1ex}]

Best Answer

It's the Veelo chapterstyle from the memoir class.