"Modern software releases patches and updates incrementally,
meaning you only have to download the code that is different. This
allows for much smaller and more effective downloads. Patching
systems such as this have been around since software had version
numbers. Why then does Firefox require you to download the full
program every time a new version is released?
"Updating from v1.0.2 to v1.0.3 requires a 4MB download for a
meager .01 version update..."