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While in the closed issue #473 it is stated that the renaming of the SCApp to "SuperColliderCocoa" is intentional to allow the parallel usage with the IDE, this whole naming scheme creates incompatibility across versions (at least on OS X).
Currently, the only stable version is SC3.5.5, which is (properly) called SuperCollider and uses the extension folder of SuperCollider
SuperCollider 3.6 compiled with the IDE is also called SuperCollider, but doesn't implement the same functionality, which is why it throws sclang errors on startup (e.g. when trying to add to the library menu).
SuperCollide 3.6 compiled without IDE (using SCApp) is renamed SuperColliderCocoa, which makes it use a different startup file than 3.5.5, while it actually should use the same (being the newer version of the compatible application).
Additionally it needs to be said that the renaming to SuperColliderCocoa is also quite awkward, just as awkward as if Firefox were called FirefoxCocoa or SuperCollider were called SuperColliderKDE.
josh and me discussed this and agreed on using a separate name for scapp. personally i neither care, nor do i want to spend my time on osx-related issues, so whoever wants to mess with the names, please go ahead, change ...
Hmm, I see. Not sure either way, me, since I don't have direct access to mac, so count me as an abstain...