OS X: Put your apps on a diet

Although I have a solid 15 years of Windows-knowledge under my belt, I regularly find something new when working on the Macintosh. One cool thing (for the Windows-folk and registry hackers) is how OS X manages applications. First, you do not get InstallShield binaries where you have to install hundreds and thousands of files in a multitude of directories. Secondly, you do not have the concept of a registry which gets bloated.

On OS X application-installs are delivered via a DMG-file – a disk image format. The format allows secure password protection as well as file compression and hence serves both security and file distribution functions. When opened, DMG files are “mounted” as a drive within the Finder – so think of it just as mounting an ISO in Windows. Just a lot easier (no need to install VirtualCD or Nero or any other app being able to mount images) – out of the box.

OS X applications obviously need to store user preferences – those are files stored in the ~\Library folder of the user’s home directory. When you need to un-install an application, either that application automatically removes those preferences, or you can just manually delete the, or you use an uninstaller such as AppZapper – which automatically removes any application dependent files.

What I did not know was that applications are distributed in the Universal Binary Format – ever since Apple introduced Intel-based Mac’s (such as the MacBook Air), most applications ship nowadays with the Intel and the PowerPC version in one bundle file. OS X will then decide which runtime to execute when you launch an application. I also found out that generally most applications also ship with a number of languages bundled with the application (in many instances up to 17 different languages).

This creates a lot of bloat and wastes a lot of hard-drive space – and here Xslimmer comes to the rescue:

Xslimmer is a small tool which analyses the installed applications and then removes not required files from the bundled application. Since in my case I only require applications in US-English and as an Intel-binary, I put Xslimmer to the task and remove the excess fat. It took about 10 minutes to “slim” 60 applications and free up 3GB of disk-space (this is especially important on my 80GB MacBook Air). iTunes used to be on 120MB and sits now at 34MB – the same applies to all mac:office applications. Aside from freeing up extra space, it appears that applications launch quicker.

The cool thing about Xslimmer is, that you can slim any system application (such as Safari, iTunes, iMovie, Garageband etc) – since it only removes the unneeded files, all applications are fully functional. I did notice that in one instance (Araxis Merge) the application did not work – for this Xslimmer provides a daily updated “black-list” of applications you should not slim.