Scalability of a BIRCH system. On a PC, File Services, Processing and Display would all reside on the PC. Alternatively, a Unix/Linux workstation might remotely-mount filesystems, but carry out the processing and display steps. For larger multiuser systems, File Services might be remotely-mounted onto login servers, where programs actually run. Windows generated by programs would appear on the local display, which could be an X-terminal or other thin client, or a PC running X11 display software. At login, BIRCH determines the OS/hardware platform of the login host (eg. Linux-Intel, Solaris-Sparc or Solaris-AMD64) and provides the user with platform-specific binaries, libraries, paths and environment variables.