My experience has been Windows Forms in VB, using SQL Server as a back end, and Windows Phone Silverlight, with which I have not used any data services other than Isolated Storage. I need to create an application for both PC and Mac (no Mac experience at all). The application will need to use local, relational data - nothing online, data stored on the local machine.
I was thinking I would have to learn Mac development, but then it occurred to me that Silverlight is cross-platform. Keeping in mind that my only Silverlight experience is with a couple of Windows Phone apps (simple ones), can I use Silverlight to develop an out-of-browser application that will run on both Windows and Mac, and be able to access a local database on the machine? If yes, what database can I use, since I'm sure SQLExpress, which I had been thinking of for the PC version, will not work on Mac?
The database could potentially get rather large, and I've never used XML to store data before, so I'm not sure if XML is the way to go. Thanks in advance.