The DMERGE is a tool which can be used to merge multiple .NET assemblies into the single one. In general, DMERGE is a Graphical User Interface build on the top of ILMerge, which has been developed by Microsoft research team. Originally DMERGE has been developed by DAENET team to extract the user controls (build as ASCX files) from ASP.NET web application and to merge them in single assembly which can be used in another ASP.NET application.
Here you can download the DMerge Tool and the User Documentation:
http://developers.de/files/folders/1269/download.aspx