  Although M dwarfs are the most common stars in our stellar neighborhood they
are still among the least understood. This class of objects is dominated by
dramatic changes: in their interiors (fully convective, with implications in
angular momentum evolution), in their atmospheres (crossing temperatures where
dust settling occurs), and in their nature (including both, stellar and
substellar objects).
  Populating efficiently our solar neighborhood, they are very well represented
in the databases coming from new and more sensitive surveys that provide
photometry at many wavelength ranges and cover large areas of the sky (few
examples among many others are GALEX, SDSS, 2MASS, WISE and VISTA).
  In this context of opulence of objects and data, the Virtual Observatory
comes in naturally as an excellent framework to efficiently advance in the
knowledge of M-type sources. We put special emphasis in the benefits of using
the new capabilities of VOSA (Virtual Observatory SED Analyzer, Bayo et al.
2008; in operation since 2008 and in constant development) to study large
samples of candidate and confirmed M members of Chamaeleon I.
