There is quite some hype around in-memory technology and I admit freely: it is simply amazing. It also made me think of some software I wrote back in 1997.
In school I was asked if I could do something about the manual tasks in the library. There were index cards and not much more. There was also no good free libraray management software back then. So since I had two months of summer holidays and nothing to do I sat down and created one.
Written in Pascal it features an extensive and simple user interface supporting mouse inputs and hotkeys. There is a simple authorization concept for admins, librarians and users. And, back to the initial point, data is stored in-memory allowing very fancy things like instant incremental search results while typing. It will print barcodes and offer quite some customizations. And it was used for several years.
If you are interested you can look at a short overview or also a version with me talking (in German).