DATAllegro was a company that specialized in data warehousing appliances. It was founded by Stuart Frost in 2003 inspired by and as a competitor to Data warehouse appliance pioneer Netezza.[1] DATAllegro - like Netezza - used open source software stack (Ingres DBMS running on Linux). Microsoft announced it had acquired DATAllegro as of September 2008.[2] SQL Server Parallel Data Warehouse (PDW) is the successor product to DATAllegro on Windows Server using a version of the SQL Server database engine.[3]