Hi
I noticed you switched to svn, so I pulled the latest version from svn and tried building with the Xcode project file.
But there were some issues.
There was a problem with the path of the OISMultiTouch.h file.
And I use Snow Leopard, the default compiler of Xcode in Snow Leopard is GCC 4.2, which isn't compatible with the 10.4 SDK.
I manually had to change the compiler of all the projects to GCC 4.0 for it to work again.
I think this will still work in Tiger and Leopard, but you may need to test that.
I made a patch with the fixes:
http://pieterhoste.be/ois/patch2It might also be a good idea to add some ignore properties, for example to the XCode-2.2 directory you can add "build", so the build directory is ignored by svn.
Also in the OIS.xcodeproj directory, you can add "*.pbxuser" and "*.mode1v3" to the ignore list.