I found this while looking for a spreadsheet that I could embed in a CGI app. It's an ajax spreadsheet based on Dojo 0.3.1. I don't know if it's going to be as advanced as you'll need for your spreadsheets, but I believe it works on your machine with your storage, not online storage. Plus you can download it, so you get all source.

Not a Perl solution but it may work for you just the same.

HTH!