omniORB 3 should run on IRIX 6.4 and 6.5 with the latest MIPSpro 7.2.1
compiler. It is recommended that you also apply the latest patches to the 
compiler - see mips_irix_6.5.n32.mk for more details on patches.

According to the information provided by smant@nlr.nl (Geert Albert Smant),
and James Riden <jamesr@europe.com>, the SGI linker has some peculiar
requirements on the order in which share libraries are specified on the
command line:

    1. Two libraries cross reference each other, as it is the case with 
       -lomniORB2 and -ltcpwrapGK means that -lomniORB2 has to be
       repeated after -ltcpwrapGK
    2. Multi-threaded programs must have -lpthread as the last option
       on the command line.

 To satisify #2, we arrange in OMNIORB2_LIB that -lpthread is the last
 option. So as long as in a dir.mk, the $(CORBA_LIB) is the last one
 in the assignment to libs, this condition is satisfied. 
 E.g.
      $(eg1): eg1.o $(CORBA_STUB_OBJS) $(CORBA_LIB_DEPEND)
        @(libs="$(CORBA_LIB)"; $(CXXExecutable))

 There are also some caveats on building and running 64-bit binaries.
 See mips_irix_6.5_64.mk for more details.

For Irix 6.2 and 6.3, the mips_irix_6.2_n32.mk can be used.