You can use the & kde; libraries to write commercial and closed source as well as commercial and open source software. If you want to write open source software you can use the & Qt; free edition. But if you intend to write closed source software you may not use the & Qt; free edition; you need to obtain the & Qt; professional edition from Qt Software.
Pode empregar as bibliotecas de & kde; para escreber software comercial e privativo así como comercial e libre. Se escrebe sóftware open source pode empregar as & Qt; free edition. Pero se escrebe software privativo non pode empregar as & Qt; free edition, deberá obter a & Qt; professional edition de Troll Tech.