In order to make Dynamic (Web) TWAIN accessable from any COM-enlightened program languages, such as VC, VB, Delphi and VBScript, only variant compliant IDL data types are used in the Dynamic (Web) TWAIN interface.
The following table is the mapping between different languages:
| COM Type | Visual Basic Mapping | Java(J++) Mapping | C/C++ Mapping | Delphi Mapping | C# .NET Mapping | VB .NET Mapping |
| VARIANT_BOOL | Boolean | boolean | VARIANT_BOOL | WordBool | bool | Boolean |
| double | Double | double | double | Double | double | Double |
| float | Single | float | float | Single | float | Single |
| long | Long | int | long | Integer | int | Integer |
| short | Integer | short | short | SmallInt | short | Short |
| BSTR | String | java.lang.String | BSTR | WideString | string | String |
| DATE | Date | double | DATE | TDateTime | System.DateTime | Date |
| IDispatch* | Object | java.lang.Object | IDispatch* | IDispatch | Dispatch | Object |
| IUnknow* | Interface reference | com.ms.com.Variant | VARIANT | IUnknown | object | Object |
| VARIANT | Variant | com.ms.com.Variant | VARIANT | OleVariant | object | Object |
| CY/CURRENCY | Currency | long | CY/CURRENCY | Currency | decimal | Decimal |
Out of the consideration of convenience, the Visual Basic data types are chosen to present the data types in this document. Using the preceding table, the VB data type can be easily mapped to C++, Delphi, C#.NET and VB.NET.
For other programming languages, please consult the accompanying document. Dynamic (Web) TWAIN is designed to be used in any COM compatible development environments.