Drawing rectangles on a grid in a web browser

I would like to create an online, simple WYSIWYG drawing editor allowing people to draw rectangular shapes. I'm thinking of a grid which the lines and points can snap开发者_高级运维 on to, ensuring that the lines are strictly vertical or horizontal. I will be parsing the rectangular shapes to obtain some area calculations and compute certain things. How can I achieve the drawing ability? The new canvas tag is good but people have been telling me that IE does not support it. I found some Java applets but I have never programmed in Java before. Is there a way to do this using pure javascript or jquery? Does ASP.NET help at all?

Thanks.

You're absolute best bet is to learn flash or silverlight. Trying to do this in plain old html / javascript is going to be a huge PITA... if you even get it working.

For vertical and horizontal lines you can simply use thin divs with a background, defined size and absolute position. Really simple to code and will work everywhere. You'd need canvas for anything more than strictly vertical/horizontal ones though.

You can definetly use canvas, and emulate it on IE with one of the libs:
http://code.google.com/p/gwt-canvas/
http://excanvas.sourceforge.net/
But take care on performance. Chris Lively has a point.