Apple has updated their developer tool for creating Carbonized applications, the CarbonLib SDK, to version 1.2f3. The new version allows developers to more easily create Carbonized applications that are compatible with Mac OS X and OS 9. According to Apple:
The latest prerelease version of the CarbonLib 1.2 SDK for Mac OS is now available to all ADC Members. This SDK provides all the files needed to begin Carbon development. CarbonLib 1.2 supports Mac OS 8.6 and greater.
The CarbonLib SDK is only available to Apple Developer Connection members. Membership into the ADC is free, and you can register, and find more information, at the Apple web site.