CIPL has a good post on risk in development on copyleft platforms. The article discusses some of the legal issues faced by developers can approach an open source platform or program without being caught in the copyleft “license†with a duty to disclose if they retransfer their products.
The article is based on a working paper by Free Software European Legal Network and concludes that “entities that do not desire to disclose code or force their customers to do so, or otherwise conform to copyleft obligations, working with copyleft platforms and programs presents a very significant and uncertain, risk-reward equation. “