NethServer is a community effort, sponsored by a company (Nethesis). Its business model is to sell software, support, and services to other companies, customers, and resellers. Part of the revenue is used to fund development of NethServer, official site hosting, community initiatives, sponsoring, and so on. Community and company have the same target: making NethServer better and more successful, and NethServer benefits enormously from the resources that the company invests into it.
The company pays NethServer coders to write features the customers need and works with the community to make NethServer a better product. Because the company works in the open and as part of the community, and because the code is released under the GPLv3, NethServer itself continues to be free. That’s a virtuous circle and everybody wins!
Taken from this article