 With the development of the rail network in the 19th century, Roskilde became an important hub for traffic with Copenhagen, and by the end of the century, there were tobacco factories, iron foundries and machine shops.Among the largest private sector employers today are the IT firm BEC (Bankernes EDB Central) and GPI (Glim Plastic Industri), specializing in plastics.The Risø research facility is also becoming a major employer, extending interest in sustainable energy to the clean technology sphere.