\begin{frame}{What is Mercurial?}
  Main features:
  \begin{itemize}
  \item<1-> fast, distributed revision control system
    \begin{itemize}
    \item robust support for branching \alert{and} merging
    \item free and open source
    \end{itemize}
  \item<2-> installers for Windows, Mac OS X, Linux, \dots
    \begin{itemize}
    \item TortoiseHg is a cross-platform graphical frontend
    \item MacHg is a fast native Mac OS X frontend
    \item plugins for MS Visual Studio, Eclipse, \dots
    \end{itemize}
  \item<3-> very user-friendly
    \begin{itemize}
    \item extensive built-in help for all commands
    \item command set resemble CVS and SVN
    \item destructive commands delegated to extensions
    \end{itemize}
  \end{itemize}
\end{frame}