In any file, you can combine information from multiple sources--a remote table of orders on a Web page and an internal database of inventory and prices, for example. And you can write back to some sources, such as files and relational databases, in addition to reading from them.
For collaboration, you enter via the QuickShare datasource included with the Juice Server.
I built a quick spreadsheet, then selected the cells I wanted "Bob," my user, to be able to update.
I published them to the server in a topic called "Revenue for Bob." Next, I opened a separate copy of Excel, hit the subscribe button and chose the topic Revenue for Bob (see screenshot). The data was immediately pulled into the spreadsheet and color-coded to show which cells I could and could not update. The color-coding is, of course, user-configurable.
Overall, Juice provides a rich set of features for enhancing spreadsheets. Although the client is a bit rough around the edges--it requires a programmer or a true power user for exceptional spreadsheets--it's an excellent alternative to custom fat clients, if you can stomach the price.