WHY I USED TO PREFER PERMISSIVE LICENSES AND NOW FAVOR COPYLEFT

Summary from the TLDR newsletter

Free open source software is usually published under one of two major categories of copyright licenses: permissive licenses, which freely share with everyone, or copyleft licenses, which freely share only with those who are also willing to freely share. Copyleft creates a large pool of code that developers can only legally use if they are willing to share the source code of anything they build on it, making it a very broad-based and neutral way of incentivizing more diffusion. It does not favor specific actors nor create roles for active parameter setting by central planners.