The Open Library collection of (and free to access) book info including many free full-text eBooks has just added the OCLC number and a direct link to the WorldCat bibliographic record for more than four million editions in their collection. The
The four million number comes from many titles in the Open Library having multiple editions available. OL provides free access to more than one million books.
The technology that added the OCLC Number to Open Library records, oclcbot, was written/developed by Bruce Washburn at OCLC Research. If you want to read about how oclcbot works, this OL blog post by George Oates has details.
Each OCLC Number is hyperlinked so accessing the complete WorldCat record with bibliographic info is only a click away.
By the way, when you access an eBook from Open Library you can download the full text , in some cases click and send directly to a Kindle device, or read online using the superb Online Library BookReader.
+ More From oclcbot to Come
+ Some eBooks available available from the OpenLibrary are only available to the print-disabled. Another collection of books (approx. 80K are only available to those with library cards from libraries participating in a cooperative program that launched about three months ago.
Kudos to the Internet Archive and OCLC on the collaboration.