While reading Geoff Nunberg's...ah...crisp assessment of the current state of GoogleBooks metadata--with which I thoroughly agree--I discovered Hathi Trust Digital Library, which "was conceived as a collaboration of the thirteen universities of the Committee on Institutional Cooperation and the University of California system to establish a repository for these universities to archive and share their digitized collections." Unfortunately, searching across texts (currently described as "experimental") is limited to OOC works. Right now, quite a lot of OOC works are limited to search-only; a quick test using "tale reformation" as the keywords turned up unviewable editions of very OOC novels like From Dawn to Dark in Italy. I'm spying some familiar problems with the metadata--Tales of the Persecuted, an undated collection published in Philadelphia, turns up with a date of 1800 (which is clearly wrong). And, as in GoogleBooks, there are orphaned volumes (e.g., Catherine Sinclair's triple-decker Cross Purposes). In books identified as search-only, the results indicate that there was a hit...but not what the hit was. Which, I have to say, is even less useful than GoogleBooks' much-loathed "snippet view." That being said, I prefer the screen layout. Books can be viewed as PDFs, text (somewhat cleaner than GoogleBooks' or the Internet Archive's plain text), or images.
It would be nice if the catalog search function would let users search by library.
It's too early to say much about the content, although there should be an incredible resource here once everything is uploaded and made available.