A: Anyone who's worked with Microsoft RDS or Citrix XenApp is probably familiar with the term "seamless windows." A seamless window in these products is a published application that has been provisioned so that only the application itself is visible. The term seamless window is specifically used by Citrix—Microsoft's similar approach is called a RemoteApp.
Seamless windows are necessary because every published application operates inside a Windows shell that shouldn't be visible to the user. Thus, the published application must be deployed with a size exactly matching the application's window size, creating the "seamless" effect.
Some applications, however, work better when they're installed and run on a user's local computer. Users can easily work with these local applications when they're also working inside their local Windows shell. The same isn't true when users work inside a remote virtual desktop. Reverse seamless windows provides a way to seamlessly expose locally-installed applications while users work within their remote virtual desktops—hence, "seamless windows" in reverse.