A while back before my subscription expired, :(, I noticed that if I tried to view REST web services on my Mac (10.8.2), I got an error from MyEclipse saying it was an unsupported platform (yet the list included Mac OS/X).
Trying to view SOAP Web Services worked fine on the Mac.
The REST Explorer in MyEclipse is a browser based application. However, there are restrictions on what browser based applications can access from other domains – basically to protect against XSS. The cross site access needs to occur when your application is being tested by the REST explorer.
We have been able to turn off this protection exclusively for the REST Explorer, which is based on Mozilla. Unfortunately the mozilla builds we have to use are not available on OSX Cocoa which is why you see the error.
Turning off the protection in other browsers or looking at doing this some other way is something we are investigating for the upcoming release of MyEclipse, unfortunately there is no simple workaround for this.