To find out what release of IRIS Performer is currently installed
  on the system do:

  % versions | grep performer

  and you will see a list of all IRIS Performer subsystems that are
  currently installed.  Note that you might see execution
  environments and compatibility DSOs for older releases of IRIS
  Performer -- this is what allows you to run any IRIS Performer
  executable, regardless of the development release you are currently
  using.

  To find out which version a given IRIS Performer DSO library is do:

  % elfdump -L lib.so | fgrep IVERSION

  and you will see the DSO version number of the library.  Note: DSO
  version numbers are NOT the same as IRIS Performer product release
  numbers.  DSO numbers are X.Y.Z where the X must change with each
  change in binary compatibility, where the Y changes to signify a
  binary compatible version, and the .Z is an additional tag.  The
  mapping of IRIS Performer releases to DSO numbers is:

  IRIS Performer release      DSO lib version
  -------------------------------------------
        1.0                     sgi1.0 
        2.0                     sgi2.0 
        2.0.1                   sgi2.1
        2.0.2                   sgi2.2 
        2.0.3                   sgi2.3 
        2.0.4                   sgi2.4
        2.1                     sgi3.0 
        2.1.1                   sgi3.1 
        2.1.2                   sgi3.2

  Each release of IRIS Performer includes the versioned DSO libraries
  from previous releases for each binary compatible group.  Upon
  program startup, rld will find the proper version of the IRIS
  Performer library for the current executable.  These DSOs are
  installed under /usr/lib/ and /usr/lib/Performer.

  ex:
      /usr/lib/libpf_ogl.so.2 
      /usr/lib/libpf_ogl.so.3
      /usr/lib/libpf_ogl.so.4

      % elfdump -L /usr/lib/libpf_ogl.so.2 | fgrep IVERSION
          [34]    IVERSION sgi2.4

  To find out which version a dynamically linked IRIS Performer
  executable was made with do:

  % elfdump -L progname

  and you will see a list of the DSOs required by the program and
  their DSO version number.