In Figure 4 the SharpMap layer lies on IIS and shares the server side processing with ASP.NET. The SharpMap library renders a bitmap by processing the vector data on PostGIS. This is then streamed to the user interface as an image. To render the maps, SharpMap uses the Application Programming Interface (API) of the Graphics Device Interface (GDI) which is a core component of Microsoft for representing graphic objects. All the great styling feature like the brushes and pens can be used to render maps that display symbology for various purposes. All this processing is done at the server side complemented by visual studio which provides an Integrated Development Environment (IDE) for developing applications on desktop and web platforms. Therefore, like many other mapping libraries and Web Map Services (WMS) [22] servers, SharpMap has support for generating thematic maps with different styling options and can be used to query maps dynamically from many database providers and file systems.