Hello Erik and Doug,

Thank you for your replies.

On Jun 5, 2011, at 7:58 PM, Doug Browne wrote:

> Nobumi, what an odd statement. I have just double clicked eight documents, each made with a different application and they all opened with the app that made them.

Well, what has changed between 10.5 and 10.6 is that the "creator" (a kind of resource) attached to each file is no longer working with Finder of 10.6. This is only the extensions, such as ".rtf", ".doc", etc., which indicate the applications that should open files. It is said for example in
<http://www.macworld.com/article/142937/2009/09/snowfiles.html>:

Each application includes a creator code with the metadata (data about data) for the files you create. In all versions of OS X prior to 10.6, it’s this information (assuming you don’t override it using the Finder’s Open With contextual menu) that lets the system know which application to use to open a given document, regardless of its extension.

In Snow Leopard, creator codes no longer play this role—while they can still be assigned by the creating application, they (probably) won’t work as you expect them to, especially if you’re a long-time Mac user.

That’s because Apple has arbitrarily changed the role creator codes play in determining what application will open a give document. In Snow Leopard, applications are opened based on the user’s setting in the Get Info window; if that setting hasn’t been changed, then the document is opened by an application deemed to handle that file type, using information maintained by the system’s Launch Services routine.
....

For files such as MS Word created files, there are no special problems (in general), but for rtf files especially, this may be an important issue, because there are many applications which can create rtf files. I think the default setting is that it is TextEdit which opens these files. Many of you changed it at sometime, to make NWP open them, but you probably forgot that. But there are for example rtf files which were created by Jedit X; now if you have set rtf files to be opened with NWP, those which were created with Jedit X (or any other editors of this kind) will be opened with NWP if you simply double-click on them in Finder. If you want to open them with Jedit X, you must use the context menu "Open with...", and I find this cumbersome...

Best regard,

Nobumi Iyanaga
Tokyo,
Japan