There's also the Microsoft Excel Viewer for people who don't have Excel, but I don't know if they even support it anymore. And it's not exactly interactive.
I saw this through a search, but it appears Microsoft or whoever created the software is still supporting. Problem with the viewer, you can save any changes made to the workbook.
You can also check out the open office suite (which I haven't tried), or Google's Spread****s app, which isn't nearly as robust as Excel.
Can Excel workbooks with macro coding & formulas be used on Open Office or Google Spreadsheets?
I saw this through a search, but it appears Microsoft or whoever created the software is still supporting. Problem with the viewer, you can save any changes made to the workbook.
Can Excel workbooks with macro coding & formulas be used on Open Office or Google Spreadsheets?
So you want to distribute an interactive WB, but not allow saved changes?
Excel's never really been set up for concrete protection, so your options are pretty much limited to the end-user's honesty. You can do a lot with VBA that will keep most people honest, but it's kind of moot if they don't have Excel.
I don't think GS support VBA. I am not sure about OO, as I've only used it once.
Take a look at the compilers, as it seems that's the direction you might want to go.