Scania is a Swedish producer of heavy vehicles situated in Södertälje outside Stockholm. It shares its name and logotype (a griffin) with Scania (place), and was based there from 1891 to 1911 as a manufacturer of bicycles and automobiles.
Scania merged with VABIS (Vagnsfabrik AB i Södertälje, "Car factory Inc. in Södertälje") 1911, and manufactured cars and trucks until 1969, when it merged with SAAB, an aeroplane and car manufacturer, and became the heavy vehicle division of Saab-Scania.
During the nineties the company was split in three pieces, Saab Automobile AB (now a part of General Motors), Saab AB (aero/defense), and Scania AB.
A merger between Volvo (the Swedish heavy vehicle corporation, not the Ford trademark) and Scania was stopped by the European Union in 2000.
Scania is very profitable. In fact, they haven't reported a loss since before World War II. And it's no small profits either - they like to call themselves "the most profitable car factory in the world". And that's probably true.
Their secret is a highly modularized system, allowing them to cut costs and allow a great deal of customization. All manufacturers do this - but not to this extent. These things are like LEGOs.
That, and great management.