Specifically, the french contribution to this mission, consists in supplying 2 scientific instruments:

OMEGA (Observatoire Martien pour l'étude de l'Eau pour les Glaces & l'Activité): Visible and near-infrared spectro-imager.
SPICAM (SPectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars): a spectrometer with an ultraviolet channel and an infrared channel.

and a strong participation to the development of a third:

ASPERA-3 (Analyser of Space Plasmas & EneRgetic Atoms): Neutral atoms imagery: study the process of the martian atmosphere loss.

CNES financed and provided the technical follow up of those instruments developments realized by scientific laboratories.

Mars Express was launched on June 2 2003 from Baïkonour by a Soyouz launcher with a Fregat stage. The satellite realized the Mars Orbit Insertion on December 25 2003.
No contact could be made with Beagle after its release.
On September 15 2005, ESA announced that the mission was extended for 23 additional months.
On February 23 2007, ESA announced that the mission was again extended, pushing back the mission end date to early-May 2009.
On February 4 2009, ESA announced that the mission was again extended, pushing back the mission end date to the end of December 2009.
On October 2 2009, ESA's Science Programme Committee approuved the extension of MARS EXPRESS mission operations until December 31 2012.
On November 19 2010, ESA's Science Programme Committee approuved the extension of MARS EXPRESS mission operations until December 31 2014, extension submitted to a review in 2012.