Some useful links:

The first site without which we would not be there: http://www.valvesoftware.com/

Frere d'Arme's blog, Wilson Chronicles's developer: http://freredarme.blogspot.com/

French website about Steam ® : http://www.steam-france.fr/

Games and mods development for PC; XBOX® Playstation® and Nintendo®: http://www.moddb.com/