Xslimmer 1.7 now available, fully compatible with Snow Leopard

Xslimmer 1.7 has just been released! It supports 64-bit binaries, honors code signing rules, is able to handle and create native HFS-compressed files and adds many other improvements that will continue to provide a worthwhile and reliable experience to Snow Leopard users (as well as to all others that choose not to upgrade to the latest OS yet). Read on for the gory details!

Universal Binaries are so 2008, aren't they?

Well, unfortunately they are not. Or, should we say, fortunately they are not. Universal Binaries were a key technology that allowed Apple to transition from PowerPC to Intel CPUs in the most awesomely flawless technology adoption ever. The same Universal (or, as they are affectionately called, "fat") Binaries are being put to work again to ensure that Snow Leopard and its apps run flawlessly in all compatible Intel machines, including 32-bit and 64-bit ones.

So instead of packaging binaries in a bundle that contains PowerPC and Intel versions of the code, it will now become usual for developers to provide the 32-bit and the 64-bit versions of the same code. The 64-bit version will be used in 64-bit computers, whereas the 32-bit code will run in CPUs that are not able to handle 64 bits. There is no magic way for the system to transform one into the other, so no matter what computer you have, chances are many of the apps you install will contain code that will be ignored and never will run.

But it gets more interesting! Snow Leopard is truly awesome, but there is no reason for developers not to support Leopard if they can. True, some apps will take advantage of Snow Leopard exclusive technologies such as Grand Central Dispatch, OpenCL or some other new APIs; however, many others won't need these innovations yet and will still support Leopard. But Leopard does run on PowerPC machines, so developers should include a PowerPC version of the code if they want to support the same hardware requirements as the OS. As a result, we are starting to see applications that include not two, but three architectures: Intel 32, Intel 64 and PowerPC. This is the case for some very popular apps such as Tweetie for Mac or the latest version of Apple's own Airport Utility.

Xslimmer was designed to handle these situations, and it has now been tested and optimized for the scenarios above so it will always keep the best version of the code that is available for your Mac. If you own a 64-bit-ready Mac, then Xslimmer will preserve the 64-bit version of your applications' code - when it's available.

Won't Xslimmer break 64-bit applications? What about code-signing?

As discussed above, Xslimmer carefully analyzes your applications and selects the best possible architecture among those available. This is done in a per-application basis, and not following some batch process that blindly keeps a single combination. Analysis includes evaluation of signed resources: code-signing rules are fully honored so that only binaries that can be safely modified will be processed.

Extreme care is applied when slimming, and the operation is performed in the most friendly way. Your slimmed applications are registered again for you in the internal OS databases - your keychain authorizations are preserved, and you don't even need to restart your Mac after slimming it.

But Apple applications are already compressed!

Snow Leopard achieves significant space savings by using transparent file system compression. In fact, all system applications and utilities are installed in a compressed state, although they are transparently uncompressed on the fly without the user ever noticing. Xslimmer 1.7 recognizes and supports this type of compression: if a compressed application is slimmed, then it will be recompressed automatically. Therefore, all system applications in Snow Leopard will still benefit from additional space savings if they are slimmed, without affecting their compression status.

When running on Snow Leopard, Xslimmer will always show you the actual size your applications take up in your disk, and not the uncompressed size as reported by Finder and other tools. This way you can be absolutely sure about the savings you achieve.

We have even taken this technology a step forward. A new option in Xslimmer 1.7 will allow you to compress slimmed binaries that were not originally compressed. This way, your installed third party apps can also benefit from this awesome new HFS+ compression technology in Snow Leopard.

Ok, I'm sold - I'll give it a try!

Wonderful! We've always worked hard to prove that your choice of Xslimmer is really the best option for your slimming needs. In Xslimmer 1.7 you'll find many features designed to slim your Mac easily and with total peace of mind. These include:

Strip out unneeded localizations - As usual, Xslimmer 1.7 will remove translations you don't need, achieving great space savings.

Visual indication of architectures - Another new feature in Xslimmer 1.7, you can now see what architectures an app contains and what the resulting architecture is: Intel 32, Intel 64, PowerPC 32 or PowerPC 64.

Downloadable blacklist - for those apps that check themselves (for anti-piracy reasons, usually) and refuse to start after they have been slimmed. We test every report from other users about malfunctioning apps.

Your personal exclusion list - for folders in your disk that you don't ever want to mess with, for whatever reason.

Integrated backups - designed to let you test your slimmed apps with the confidence that you'll be able to recover them in one click.

Extreme compatibility - Xslimmer 1.7 has been fully optimized for Snow Leopard, but it will still run in Panther, Tiger and Leopard.

So, no matter whether you are a longtime Xslimmer fan or have come across it recently, now is an excellent time to check the combined space savings that Snow Leopard and Xslimmer will bring. We hope you like Xslimmer 1.7!