> Which means either pointer+length get packed into their own structure to avoid mix up errors, thus requiring conversion function calls across libraries, or th

> Which means either pointer+length get packed into their own structure to avoid mix up errors, thus requiring conversion function calls across libraries, or they are given separately manually, thus opening the door to the copy-paste mistakes from pointer+bad length that they are supposed to protect against. No, we were talking about compatibility/modularity. You're shifting the topic. > Qt is as locked-in as any LPGL 3 FOSS project is. I'm not speaking about licenses lock-in, but about lock-in from an engineering point of view. Are you aware of any significant Qt projects that don't have "Q" all over their codebase? (And yes, by contrast to GPL, I believe you can use LGPL libraries without suffering a terrible amount of (license) lock-in)