Buenas noches from here 

FlowChartX is an ActiveX control, i.e. it runs in COM containers such as VB6, Delphi or MFC apps. It can be used in .NET too via the COM interop.

FlowChart.NET is a native .NET control, as its imaginative name suggests. It's the right choice for a C# project, because with it you are getting APIs using the native .NET types such as Color, Graphics, etc. (With FlowChartX and COM interop you would get types such as HDC and OLE COLORs imported in .NET as integers). If you care for security, the .NET control is the definite choice, because the ActiveX one will always require "full trust" .NET permissions to run.

I hope this helps,
  Stoyan