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Using Google’s Spreadsheet API, you can create a simple CMS for your website extremely easily. It’s as simple as making a new sheet with key/value pairs for any fields you want dynamically populated. You can then access the data from javascript via the JSON API. Any updates to the spreadsheet will be immediately reflected in your page.

The only downside to this approach is that the content of your page is populated by Javascript on the client side, so search engines won’t see the content of your pages during a crawl. You could overcome this obstacle by using the PHP API to pull the spreadsheet data and render the HTML on the server side.

Simple CMS using Google Spreadsheet API – Link
Google Spreadsheets Data API – Link