Worth a look
Bigcapital is open-source accounting and inventory software for small and medium businesses. It records transactions using double-entry bookkeeping and produces financial statements and reports.
Could replace QuickBooks, Xero
Check the licence
Slowbooks Pro is a free, source-available accounting program for Windows, macOS and Linux that keeps all records in local files. It covers double-entry bookkeeping, invoicing, US payroll, inventory and bank imports, and is meant as a replacement for QuickBooks.
Could replace QuickBooks