Several companies such as Altis (pioneer in semi conductors), Snecma (world leading producer of engines for airplanes and spacecraft) and Norbert Dentressangle (transportation and logistics specialist) have already chosen Seine Essonne.

Seine Essonne is part of two international clusters : System@tic (software and complex systems) and Medicen (genomic medical research). These clusters combine high tech businesses, research and higher education centres.

Several local bodies assist companies to develop in Seine and Essonne : Maison de l'Emploi (employment and resources agency) Maison de la Création d'Entreprise (for start ups) MIVE (support for employment and training), Essonne Initiative (business development)…

The business start up zone, the Trident, supports companies and their managers in the early stages. The companies located in the Trident are exonerated from rates and social security taxes during five years.