Mainly, I have used Oracle Warehouse Builder in customer projects where the Oracle database environment is the main solution for data warehousing. It had been used mainly to collect and enhance data from other databases and pre-systems in order to establish data marts or similar data warehouse solutions for companies. The range of these pre-systems has varied from Microsoft-Office solutions to other databases (Db2, MS SQL Server, MySQL, etc.) and proprietary solutions (e.g., SAP).