Quartz Composer: 32-bit or 64-bit?
Mac OS 10.4 and 10.5
In Mac OS 10.4 and 10.5, the Quartz Composer Editor runs only in 32-bit mode.
Mac OS 10.6 and 10.7
In Mac OS 10.6 and 10.7, the Quartz Composer Editor can run in either 32-bit mode or 64-bit mode. On 64-bit-capable machines, it runs in 64-bit mode by default.
Known issues with Quartz Composer in 64-bit mode
Forcing Quartz Composer Editor to run in 32-bit mode
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