This was a neat supplement. I love libraries (even got a library degree), so this was a must-grab supplement for me. I very much enjoyed the different library examples, expanding on the rules and examples in Ultimate Intrigue to create a variety of different libraries for the PCs to visit.
I also liked the addition of the Fluency language rules, and might have to implement them in my next campaign. (Putting a rank in Linguistics and suddenly being fluent in a language has always seemed a bit off to me.)
It also includes a Library subdomain for clerics and a Words mystery for oracles, both of which I can foresee providing some character inspiration for me very soon. The various abilities of the Words mystery are especially neat.
I will say that it's a bit odd how the supplement mixes real-world information with fantastical settings; the real-world history was quite interesting, but the space might have been better used for more class options, library-based spells, or other game content. I can see a lot more potential material for this topic, so I hope this is the first Library issue of several. :-)
Formatting-wise, the issue is clear and easy to read, with lovely art/photos. There are a few minor typos here and there, but nothing that renders it difficult to understand.
All in all, a fun supplement and one I'll definitely be making use of!
