A .NET GIS solution that is fast and reliable for the .NET platform.
NetTopologySuite is a direct-port of all the functionalities offered by JTS Topology Suite: NTS expose JTS in a '.NET way', as example using Properties, Indexers etc...

DotSpatial is a geographic information system library written for .NET Framework. It allows developers to incorporate spatial data, analysis and mapping functionality into their applications or to contribute GIS extensions to the community.

DotSpatial provides a map control for .NET and several GIS capabilities including:

• Display a map in a .NET Windows Forms.
• Open shapefiles, grids, rasters and images.
• Render symbology and labels.
• Reproject on the fly.
• Manipulate and display attribute data.
• Scientific analysis.
• Read GPS data.