You’re correct. I think it’s ruby-graphviz that is (was?) under GPL.
Either way, as a lawyer, I wouldn’t let anything copyleft touch a project that is intended to be proprietary. If nothing else, the drafting of copyleft licenses is generally abominable, and prone to unintended consequences. For non-commercial projects, they’re fine but of marginal utility at best.
Either way, as a lawyer, I wouldn’t let anything copyleft touch a project that is intended to be proprietary. If nothing else, the drafting of copyleft licenses is generally abominable, and prone to unintended consequences. For non-commercial projects, they’re fine but of marginal utility at best.