Mind maps in Latex?

See TikZ manual 38 Mindmap Drawing Library

You could hack your way out using nested \left\{ delimiters and tabular environments. This is a first approximation on which one could improve further.

\documentclass{article}

\newenvironment{subgroup}
  {$\left\{\tabular{l}}
  {\endtabular\right.$}

\begin{document}

Idea General
\begin{subgroup}
  Idea Principal
  \begin{subgroup}
    Ideas Complementarias \\
    Ideas Complementarias \\
    Ideas Complementarias  
  \end{subgroup} \\[2em]
  Idea Principal
  \begin{subgroup}
    Ideas Complementarias \\
    Ideas Complementarias \\
    Ideas Complementarias  
  \end{subgroup} \\[2em]
  Idea Principal
  \begin{subgroup}
    Ideas Complementarias \\
    Ideas Complementarias \\
    Ideas Complementarias  
  \end{subgroup}
\end{subgroup}

\end{document}

I have some improvements in mind (but no time to implement them right now): one would like each “entry” in the map to be typeset on a \parbox with a \raggedright and a specific width. One would also probably want appropriate spacings (such as \\[2em]) to be automatically added. Finally one would probably like an user interface closer to enumerate and \item's instead of ending entries by \\.

I wonder if a package to do exactly this has been already implemented?

this solution with tikz trees might be helpful

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{trees}

\begin{document}
\begin{tikzpicture}[edge from parent fork right,grow=right,level distance=3cm,level 1/.style={sibling distance=4cm},
level 2/.style={sibling distance=1cm}]
\node[text width=1cm] {Idea General}
child {node {Some idea}}
child {node {Some idea}
child {node {Details}}
child {node {Details}}
child {node {Details}}
};
\end{tikzpicture}
\end{document}