What those things might be I cannot much tell you, where I'm not particularly au fait with CK.
It's free and open source but in some regards it's similar to product design/marketing. If you don't pitch it, some reviewer on the internet will make a stackoverflow post about it, and they won't know your strengths as well as you do.
A blog I read recently outlined some things to figure out: https://blog.orangecaffeine.com/the-art-of-saying-no-db012a2...
From the other comments here it sounds like some unique things you have are:
* versioned datastructures that won't change during library upgrades
* self-documenting code style
I write the library for the pleasure of it. I'm aiming to create something I think beautiful - for better or for worse, from other people's point of view :-)
I'm not actually looking for it to be used as such. It may well be, if my idea of beautiful is any good, it will come to be used, but that's... it's like a side effect.
When you paint a picture, or sculpt a sculpture, or write a song, you're not competing with other artists to make what other people will judge to be the better picture, sculpture or song.