When I see that it's GNU, I can trust in it's license, and that it's backed by an org - whether actively maintained and developed or not. My impression is that the sources are not accessible to me, personally, mainly because of legacy tech stack but also they're typically in C or C++ which is often less approachable, and often they're Linux-only or -focused.

The GNU label, (if confirmed by the project being on their official websites), gives projects an immediate boost in trustworthiness over random FOSS projects.