Moho Forum

In general, both versions are exactly the same, at least to me, never found a difference and actually, I have never looked for differences because both versions open and share files between with both OS without incompatibilities or missing features, except for this one.

In Windows you can open multiple .anme files, in OS X not.

When you try to open an anime file when you have already working on other, it needs to close your current file first, before open the other, even, in Windows you can open multiple empty files, in OSX not.
I don't know how to tell Smith Micro this, so I think here's the place to notify to them, I hope they work on this to delete the unique difference about a minor missing feature between OSX and Win.

This is an operating system issue, not AS specific. On Windows you can tell it to open apps in only one instance, like Mac does. Perhaps there is a similar option on Macs.

If you duplicate 'Anime Studio Pro.app' you can open multiple files on OS X. You can boot ASP multiple times that way, like in Windows.

But don't worry, the developers are aware about this issue.

I don't have this problem with my Mac running Mavericks.