Originally Posted by solipsism
SL still contains the localizations, the apps would be much smaller if they were removed. Xslimmer is doing a very rudimentary job of reducing the code, while SL is reducing the code in other ways, though we don't exactly know how yet.
Could they be making a single localization that can work for any and all apps installed? Are thy replacing lage bitmaps with vector graphics? Ar they cleaning up the code itself with a new compiler or making more use of frameworks? Ws shall see.
OK this is pretty basic computer science people. I have the Snow Leopard preview but I'm not going to break NDA. However, I will go on a road of self discovery and enlightenment with ya'll together.
As was stated earlier, executable code is a very small portion of an application's disk footprint. Take Mail.app for example in Leopard:
du -h /Applications/Mail.app
Mail.app takes up a whopping 289MB. This is a MacBook Pro, basically fresh off the truck from China and updated to 10.5.3. Now, look at the executable:
du -h /Applications/Mail.app/Contents/MacOS/Mail
The Mail executable is 5.7MB, or 1.97% of the overall footprint. Even if LLVM and all the other "compiler magic" (oy) in Snow Leopard reduced the executable to a measly 4K (impossible given the Mach headers, static data and load commands alone would be more than that), the bundle would still be around 284 MB.
So let's look at the resources. The real heft is in Resources:
du -h /Applications/Mail.app/Contents/Resources
So 279MB, or 98% of the footprint, is taken up by resources. Which resources then?
du -h /Applications/Mail.app/Contents/Resources/
As you can see, each localization takes up 15 MB. With 18 localizations installed by default, that's 270MB.
Now, let's look at the individual localized files. In English:
du -h /Applications/Mail.app/Contents/Resources/English.lproj/
As you can see, the largest files are nib files.
So to take an educated guess: Snow Leopard will dramatically reduce the footprint of the operating system by only installing one localization--the localization choosen by the user when they boot from the CD and choose which language to use for the installer. Other languges will be on the install disk as an Optional install. Perhaps some images will be replaced by PDF and other vector art, but bearing in mind that vector art is still much more expensive to render, and Apple has typically discouraged that route except for very simple graphics (look at the Apple Icon Guidelines), I still assert almost all the savings will come from installing fewer resources.