(Ninf-G4 -> 5.0.0)
  < New features >
  - Globus-based RPC is still available, however external modules
    (Communication Proxy and Information Services) of Ninf-G5 enable
    non-Globus-based RPC for which Globus Toolkit (Globus GRAM, Globus
    I/O, MDS) is no longer a prerequisite software.
  - In Ninf-G4, connections between a Ninf-G Client and Ninf-G
    Executables are kept until the function/object handles will be
    destructed.  In addition to this usual connection-full
    communications, Ninf-G5 supports connection-less communications
    which do not keep connections during RPC.

  < Compatibility >
  - The GridRPC API and Ninf-G API implemented by Ninf-G5 is compatible
    with Ninf-G4 except the following two items.
    + The acceptable format of the second argument (server_name) of
      function/object handle initialize functions has been changed.
      Ninf-G5 does not accept the format of Globus GRAM Resource
      Manager Contact as a valid second argument though it can be
      used in Ninf-G4.
    + An argument (error) has been added to comply with the
      specification. This change is a bug fix.
  - Ninf-G Client configuration file for Ninf-G4 is not compatible
    with Ninf-G5.
  - Due to protocol changes, Ninf-G4 client cannot communicate with
    Ninf-G5 executables and vice versa.