Is Xlsx backwards compatible?

Related questions

1. What is difference between XLSM and XLSX?
2. What is difference between XLS and XLSX?
3. Do macros work in Excel binary?
4. Can I compress an Excel file?
5. What version of Excel uses Xlsx?
6. How do I convert XLSX to Excel 2007?
7. What causes Excel to not respond?
8. How do you convert Excel 2007 to Excel 2003?
9. Can Excel handle 1 million rows?
10. How do I open an XLSX file?

Tags

1. #versions
2. #despite
3. #always
4. #format
5. #office
6. #adopting
7. #newer
8. #promoting
9. #excel
10. #documents
11. #backwards
12. #still
13. #compatibility
14. #older
15. #applications
16. #priority