What are some alternatives?
When comparing Keikai and EtherCalc, you can also consider the following products
Microsoft Office Excel - Microsoft Office Excel is a commercial spreadsheet application.
Google Sheets - Synchronizing, online-based word processor, part of Google Drive.
LibreOffice - Calc - LibreOffice Calc is the spreadsheet program you've always needed. A fork of OpenOffice.
Magic Spreadsheet - Human workforce and AI plugged into your Google Spreadsheets
Apache OpenOffice Calc - Calc, part of the https://alternativeto.
Gnumeric - Gnumeric