I released the initial ghosd and then did basically nothing with it. The problem is it's difficult to provide much functionality -- any real user of the idea will want to do their own drawing, which means I just need to give them a window and get out of the way, and that's a insignificant amount of code. I suspect the proper way to distribute this is as just a source file to drop into your application, and not as an external library.
I also vanity-searched on ghosd and discovered a discussion on a KDE site where someone requested an OSD layer for KDE and someone else observed "GTK+ apps already have the option of using ghosd". This is both true and not: I had made a point of not depending on GTK specifically to allow people like KDE to use it. But on the other hand, I do mention using Pango and Cairo, both of which are also intentionally GTK-agnostic but spring from the same GTK/freedesktop.org scene. It's hard to use any part of the stack without becoming part of all of it.
The underlying problem is that this (where "this" is roughly "a pseudo-transparency widget") isn't really application-worthy, but actually making it happen requires a bit of X-specific knowledge and I sorta feel like understanding X was already a lost art back when I first started poking around with it. This makes me think ghosd would be more useful as a tutorial with code snippets, but I lack the motivation (nor use case) to make that happen.