To check this out soon: IIPImage
"IIPImage is an Open Source light-weight client-server system for the remote viewing of very high-resolution images. ..."
Server
"IIPImage is a client-server system. The server is an Fast CGI module written in C++ that runs within a host web server such as Apache, Lighttpd or MyServer. The client application connects to the server and receives back image metadata, image tiles or dynamically generated complete JPEG images at the desired resolution and JPEG quality factor. The client communicates with the server using the IIP protocol."
Client: IIPMooViewer - Ajax Client
"This Ajax-based javascript client is compatible with Firefox / Mozilla (and other gecko-based browsers), Internet Explorer versions 6 & 7 and Safari. It is based on the Mootools javascript framework."