Excel macros in Google Sheets

Short, sourced answers to the questions people ask when a macro workbook meets Google Workspace. Every statement about Google's products links to Google's own documentation.

• Excel macros in Google Sheets: what happens to an .xlsm
  Google Sheets opens and imports .xlsm files, but it runs Apps Script, not VBA. The two ways to open the file, what happens to the macros, and what to do next.
• Macro Converter not available? Alternatives without Enterprise Plus
  Google's Macro Converter needs Workspace Enterprise Plus or Education Plus. The alternatives on Business Starter, Standard and Plus for Excel VBA macros.
• How to convert Excel VBA macros to Google Apps Script
  Excel VBA mapped onto Google Apps Script: ranges, loops, MsgBox, Workbook_Open, Worksheet_Change, email, files and databases, with Google's docs for each.
• Which Excel VBA features don't work in Google Sheets
  UserForms, ActiveX, Windows API calls, Outlook automation, files on the PC, local databases: the VBA with no Apps Script equivalent, and what to do instead.
• Convert a VBA UserForm to Google Sheets
  Google Sheets has no UserForms and Google's Macro Converter does not convert them. How a UserForm is rebuilt as an Apps Script HTML dialog or sidebar.