You need to ask yourself what exactly you are trying to do with the software. ILS (library automation) software is probably overkill. MARC import (what's been talked about- you enter the ISBN and it pulls over MARC cataloging data from LC/Marvel [most often] and/or a proprietary database) is excellent for library use, but a number of specialized books don't have LC CIP data easily available, and need to be entered by hand. #2 question is do you need circulation. Most of these systems are designed to implement electronic CIRC, which could be nice if you routinely lend books out, but could also be a hassle. Things to check: Haven't had much experience with Readerware, looked at Athaenium (you can still get the free version) but it doesn't have MARC import or seperate bib/holding records (might not matter for the private collector) Koha looked interesting, Mandarin M3 could also be used. An advantage of these is that they are set up for an internet environment. M3 has many optional modules that are $$$, Koha is all free. Both look like they could support a fairly large-size library. The downside of M3 is that (a) only runs on windows (b) if you aren't familiar with MARC, you're sunk. There's another free ILS program that sounds very good but I can't remember the name right now. I can remember that its major fault is that it is only available in Portugese (Brazil funding, written at a Brazilian university). A spreadsheet might be your best shot. A filter to convert EAN (most book barcodes) to ISBN should not be hard, it's just a matter of stripping the first two digits and then putting the proper last digit on. Downside is that you can't search or track circ.