It's really not practical to use Javascript for saving information. You can use it to download files, but that would get really nasty (imagine a download prompt every time you want to update something, as well as an upload prompt every time the webapp starts up to retrieve information).
And then there's the issue of what it's
for: A Javascript webapp is an independent script. If you run it on one computer, it saves it there. If you run it on another computer, you start from scratch and save it there. There's no way to collaborate in pure Javascript without a server, so unless you're willing to constantly send manual updates to everyone involved, you'd have as many different versions as you'd have users.
Basically, the problem is this. Javascript is a
client scripting language, meaning it's meant to do little tricks like flash a little animation or prettify a web page. What you need (from what I understand from your post) is a
server script, which gets information from users (such as through a form) and stores it in a true database on the central server. You talk about making an offline webapp, but IMHO that's just impractical -- sorry
(Plus it defeats the point: a
webapp, by definition, is an app on the web.
If you want to keep it offline, you should try making an app in C(++)/Python/Java. Macs have all three languages installed by default (GCC through XCode). If you need help with that just ask around
EDIT: Whoa, topic got locked while I was posting. Didn't notice until I finished, sorry 'bout that.
