Here is an MSDN link that describes what registration-free com is:
http://msdn.microsoft.com/en-us/library/fh1h056h.aspx
A whole walkthrough article: http://msdn.microsoft.com/en-us/library/ms973913.aspx
Registration-free COM interop activates a component without using the Windows registry to store assembly information. Instead of registering a component on a computer during deployment, you create Win32-style manifest files at design time that contain information about binding and activation. These manifest files, rather than registry keys, direct the activation of an object.
Using registration-free activation for your assemblies instead of registering them during deployment offers two advantages:
You can control which DLL version is activated when more than one version is installed on a computer.
End users can use XCOPY or FTP to copy your application to an appropriate directory on their computer. The application can then be run from that directory.
This section describes the two types of manifests needed for registration-free COM interop: application and component manifests. These manifests are XML files. An application manifest, which is created by an application developer, contains metadata that describes assemblies and assembly dependencies. A component manifest, created by a component developer, contains information otherwise located in the Windows registry.
In This Section - Requirements for Registration-Free COM Interop
Identifies operating system and .NET Framework version requirements.
- Configuring COM Components for Registration-Free Activation
Describes COM side-by-side assemblies.
- How to: Configure .NET-Based Components for Registration-Free Activation
Describes how to create an application manifest and how to create and embed a component manifest.
Related Sections - Side-by-Side Execution for COM Interop
Describes how to safely share components through COM interop services.