A few days ago, we told you that Saurik announced Cydia for Mac will be available ‘within weeks’. Today, ArsTechnica
informs us that Saurik created a new version of MobileSubstrate which has calls simply “CydiaSubstrate.” This new version can run on both iOS as well as Mac OS X on the desktop. ”
Just like you can make all these modifications on the iPhone, you can make these same modifications on the desktop,” Freeman said. “Until now, there has never been a way to easily install modifications to the system or third-party applications, as well as keep them updated.”
Developers who want to offer users some way to change how Mac OS X behaves—such as adding menu bars on more than one monitor, for instance—could use CydiaSubstrate to build the mod and distribute the resulting software via Mac Cydia.
CydiaSubstrate-based modifications can also target a particular application for modification, as well. “For instance, users that have jailbroken iPhones would like to have a modified version of iTunes that does not ask to update iOS when the device is plugged in, since the update might overwrite jailbreak modifications,” Freeman said. “Or perhaps you want to change the frequency that TimeMachine performs backups to something other than the stock settings. CydiaSubstrate makes this possible in an easy way that average users could install and update them.”