I'm using three 3rd party software to develop my own application and all of them are open source such as:
MahApps.Metro at https://github.com/MahApps/MahApps.Metro
Rhino at https://www.nuget.org/packages/Rhino.Licensing/
log4net at http://logging.apache.org/log4net/
Open Source concept seems a broad topic to me and it is not clear as far as copyright. if I decide to sell my product do I need to get a license from these providers or just giving credit and addressing them on my website would be enough? I even did contact one of the provider and his response only was that he is not a lawyer so he cannot advise me! but then said that I have to address them, which absolutely is right and fair. Yet , I'm not sure if I can sell my product. any idea?