I found a paper on Intel's site. It's from someone at Id Software.
I think it's pretty close to what's behind the cool MegaTexture name.

..basically a very optimized progressive-JPEG-like (edit: actually streams but it's not progressive in the "progressive JPEG" sense) streaming and decompression in real-time. Something very close to what I'm doing recently (as a task in a project, not as a full blown research).

For my implementation I decided to put an extra effort and make it easy to use outside the main application. This means that I'm going hide all my "nice" support classes and types and only expose the bare minimum for anyone to use the proposed functionality.

I set the goal of making a DLL out of this progressive CODEC, but more DLLs for the future.
The reason for a DLL rather than a LIB is that static linking can be pretty tricky. For example I have a global new and delete overload because I normally need 16/64 bytes aligned memory.
It's nice to be able to use a lot of my common library, but it wouldn't be nice to force headers and symbols onto other potential users.

Thinking in a DLL way also makes it easy to write at least one clean class that is easy to understand and document. The class exported in the DLL header is a bare-bones interface with a pointer to an actual hidden implementation class (aka PIMPL).

...basically I'm talking about modularity ! ..back from the dead.. saving the day where the OOP abuse complicates APIs.

cool