Web GIS.. need support for this

Hi!

Does anyone had some idea about "Web GIS"?

Actually, I know what Web GIS is all about but really don't know which way to develop the Web GIS Application.

Web GIS is using GIS on the internet, providing the users Digital Raster and Vector Charts online.. but what s/w's do I need to develop this application.

I get Raster & Vector charts from the source but I need to develop the application, which accepts data from these charts in DWG, JPG, TIFF & GIF formats and displays it on the screen.

Your help would be highly appreciated.

CheerZ,

NicK