The xrx plugin does not compile cleanly on AIX.
The file npapi.h tries to redefine a couple of sybols that are already
defined in a system header file.

Here is the error:
making all in programs/xrx/plugin...
Target "all" is up to date.








        rm -f Main.o
        xlc_r -c -O -D__STR31__ -DNDEBUG    -I. -I./include -I../rx   -
I../../.. -I../../../exports/include   -DSYSV -DAIXV3 -DAIXV4 -DAIXV5 -
D_ALL_SOURCE  -DFUNCPROTO=15   -DNETSCAPE_PLUGIN -DXP_UNIX  -
DBSD44SOCKETS     -DSHAREDCODE -bM\:SRE Main.c
"./include/npapi.h", line 44.15: 1506-334 (S) Identifier int16 has already 
been defined on line 619 of "/usr/include/sys/inttypes.h".
"./include/npapi.h", line 47.13: 1506-334 (S) Identifier int32 has already 
been defined on line 620 of "/usr/include/sys/inttypes.h".
make: The error code from the last command is 1.


Stop.
make: The error code from the last command is 2.


Stop.




Here is a quick patch I put together:
*** xc/programs/xrx/plugin/include/npapi.h.orig Fri Apr 23 14:55:03 2004
--- xc/programs/xrx/plugin/include/npapi.h      Thu Jan 27 13:42:54 2005
***************
*** 40,50 ****
--- 40,53 ----
  #ifndef _UINT32
  typedef unsigned int uint32;
  #endif
+ 
+ #if !(defined(_AIX) && defined(_H_INTTYPES) && defined(_ALL_SOURCE))
  #ifndef _INT16
  typedef short int16;
  #endif
  #ifndef _INT32
  typedef int int32;
+ #endif
  #endif
  
  #ifndef FALSE