Some of the changes are fairly small. For instance, the new version of the catalog now has a Did You Mean?
feature, which can sometimes help you find what you're looking for by suggesting a different spelling. Another small but nice feature is that the search results now show a call number. If you are looking for that specific item you'll still want to click on it to see if it's actually available, but if another book on the same subject would do just as well, you can just glance at the call number in the search results and head straight for the shelves.
Other changes are not so small. The really big one is the way details are retrieved. Before, when you wanted the details on a particular item, the entire page reloaded, so you lost your search results. Now, the new information is inserted right into the current page, so you can go ahead and look at the new details, then just scroll down to the next item, right there on the page you're already viewing. This dynamic loading has also replaced all those annoying pop-up windows in the old catalog, so for instance if you want to look at the book summary you don't need to mess around unblocking pop-up windows. The summary information is just inserted right into the existing search results page.
Go ahead and check out our new catalog, and let us know what you think!