Google Sheets was our primary tool for configuration and content authoring for way too long. Eventually, he added support for OOXML sheets, too. At some point, a long time later, we started migrating to TTL, and thank goodness for that.
The code was all open-sourced, by the way, but I'd rather not link it here because I don't really want this username associated with that company.
Any search clues? It sounds really interesting and I've been exploring the possibility of using spreadsheets as a widely understood authoring tool.
You have no idea, poor innocent soul... :(. I hope you won't touch excel-based databases, it's really awful...
I've had form templates sent to me in Excel because of the easy-to-use table layout controls. I've had games sent to me in Excel because VBA was so damn easy to program simple ideas in. I've had PoCs of algorithms sent to me in Excel because the graphical chaining of each step is so illustrative.
I've also seen the nightmare that haunts businesses who define their business logic through a bunch of interconnected Excel files. As an aside, this seems like an area ripe for "disruption" (remember when "disruption" was a bad word?), which is where tools like excel_to_code could probably make a large impact. If you could validate and test the entire business logic, as expressed in Excel files, you could reduce or eliminate the "Excel defined business rules" nightmare. If you can do this, there are thousands of SMEs that will be knocking at your door.
I personally don't use Excel for much, and I used to deride people who used it for "the wrong task", but I've recently had to swallow my pride, and accept that it's a serious power tool for most non-programmer people. I'd even go so far to say that it's the most successful "visual programming" tool out there. And by a long way.
You seem to imply that's not already the case (though many wish it wasn't)