For Intel mac, to get rid of wchar_t error message, you need
-D__UNIXOS2__:

gcc -D__UNIXOS2__ -ansi  -O  -I../../../.././include -I/usr/X11R6/include -I/sw/include   -DBuildRasterHDF -DDARWIN -DBuildRasterHPPCL -DBuildRasterNrif -DBuildRasterSun    -DBuildRasterXWD  -DBuildRasterAVS -DBuildRasterSGI              -DBuildRasterAbekas  -DBuildRasterBinary -DBuildRasterYUV               -DNGTMPDIR='"tmp"' -Di386 -DApple -DSYSV -D_POSIX_SOURCE -D_XOPEN_SOURCE -DByteSwapped -DNeedFuncProto    -c -o xwd.o xwd.c


Sun
---
The 24-bit RGB RLE portion of the driver needs work.

Parallax
--------
Compiling parallax.c with the Sun "acc" compiler results in problems
with ioctl()'s and /usr/include/sys/ioccom.h, which is not
ANSI-compatible.

HDF
---
The new driver is built upon HDF3.2r3.  24-bit imagery needs to be
checked out thoroughly.

SGI
---
The SGI rasterfile driver supports compressed and uncompressed input,
and uncompressed output. The driver needs to be modified so that it
can deal with INDEXED color on output.

A60
---
There is currently a bug in the output of Abekas RGB images but support
for input and output of Abekas RGB images is provided. YUV images are
not yet supported. The driver needs to be modified so that it can
deal with INDEXED color on output.
