I “spiked” on this a while back. You have several options, especially
once you fire up Xcode.
Rubyscript2exe worked well the first time I tried it. I even threw
Rails + FXRuby at it. I followed the documentation and I had Windows
and OS X executables, as advertised. It even handled project-relative
file paths just fine.
Now, if I recall correctly, rubyscript2exe expands its contents into
a temp directory. That took a noticeable amount of time with my app.
I think it may need to repeat the expansion every time you launch the
app, but I could be wrong.
More recently, I tried rubyscript2exe again on the same app: more
code, but nothing else different. I kept running into “too many open
files.” As far as I can tell, there is no fix or workaround on OS X.
The culprit is some rubyscript2exe file manipulation code. It does
look possible to debug and perhaps fix this code.
“Programming Ruby” (the pickaxe) chapter 21 is a good guide for
embedding Ruby. After some determined fiddling with Xcode, I was able
to write a simple nicely-packaged Cocoa app that called Ruby code.
Unfortunately, in my naive approach, Rails didn’t load its required
files. I’m pretty sure that with a better understanding of Objective-
C, Xcode, and embedded Ruby, this approach should work just fine.
In the end, the FXRuby part of my app always runs on dev machines, so
I made a .term file that kicks off a bash script. That’s really all I
need, though it bugs me that I don’t have a nice icon on in the dock.
You may have an easier time of it with RubyCocoa, but then again, I
wonder if RubyCocoa embedded in a real Cocoa app might be like
putting two Siamese Fighting Fish in the same tank?
Hope that is of some help,