Writing a web application in excel? Why not?
Before you start flaming, I'm going to tell you that I am trying to convince myself that this is a bad idea.
Basically, I'm trying to create a website with some basic accounting functions. My friend, a consultant who only knows excel, asked if this could be an excel spreadsheet instead of a web interface.
I found myself thinking, why is excel not the better tool in this case? It has all the tools a web2.0 app has (scripting, access to a db, basic formatting), and is made for accounting. You could basically use excel to write a program that fetches data from an SQL database, populates some cells, and use formulas for the rest.
Is there precedent to using excel as one would use the browser to make an ajax-y web2 app?
Why is this a bad idea?
Update: just to clarify I meant this to be more a "rhetorical" discussion. I'm not sure why the rest of the message didn't clarify that...
Answer
Well, if you made it in excel, then it wouldn't really be a web application. It would be an Excel application.
Not that that's a bad thing though. If it makes more sense to build the app in Excel, then go for it.
The problems you'll have doing it in Excel will be the same as the problems you run into with any desktop vs. web application. For example, How do you handle deploying new versions of the app? How do you handle updating the app for new (or older) versions of Excel? etc.
ETA:
If you want to avoid the bugginess of Excel VBA and the headaches of managing a desktop application, you might want to look into the Google Spreadsheets API. You can use it to create/update Google docs spreadsheets on the fly, including formulas and lots of other spreadsheet goodness. Using a hybrid of web application and Google Spreadsheets might give you the best of both worlds, depending on what exactly you need to do.