Quattro Pro is a spreadsheet program, from Borland,
currently sold by Corel, most often as part of Wordperfect Office[?].
Historically, it used keyboard commands strongly reminiscent to Lotus 1-2-3. It currently runs under the Windows operating system.
It is known to have less-capable calculations than Microsoft's Excel. For example, in many versions, subtracting dates fails to produce the number of days betweeen two dates.