Asp.net is free too and Microsoft provides a World class free tool for Development and if u know html css then u can design too with it. It’s very identical to Dreamweaver and other IDE.
Visual Web Developer 2008 Express Edition SP1 (Free for all personal, commercial purpose)
Download link : http://download.microsoft.com/download/E/8/E/E8EEB394-7F42-4963-A2D8-29559B738298/VS2008ExpressWithSP1ENUX1504728.iso
(Download this iso and install visual web developer
It has everything .Net Framework, Inbuilt Testing server and many more.)