Lukas,
Many consider their core business systems to be Accounts Payable,
Accounts Receivable, General Ledger, fixed assets, Sales Order Entry,
Purchasing, Shop floor, Manufacturing Resource Planning, Inventory,
shipping, etc., and they run these applications on a business server
like the System i on i5/OS.
Can you explain what you mean when you said,
" . . . is that right now, i5/OS can't run a Business on it's own,
which is doable using Windows and also more or less doable using
Linux"
Are these applications being built in Windows and Linux?