A library for reading and writing Excel OOXML files based on openpyxl. It was a quick hack, and I'm not currently using it. I may or may not start working on it again someday. It's likely buggy, possibly unusable, and certainly incomplete. Also it has a stupid name.
require 'xl'
wb = Xl::Workbook.new
ws = wb.create_sheet
ws.cell('A1').value = 'Hello, World!'
Xl::Xml.save_workbook(wb, 'hello.xlsx')