Blindsight (Peter Watts) largely delivers on depicting a truly alien race, where we sort of understand what it is, but with that understanding comes the realisation that we'll never be able to communicate with it, because it is so alien.
Peter Watts also includes wide variants on the human/posthuman, yet compared to the alien, they are as alike as twins. A real achievement in hard SF.
He also has a fair amount of web support for this and other novels at his website. Pdf
here. Especially fun black humour presentation
here.