GIFTool is a tool for GIF89a transparent option and interlace mode.  For
instance 'giftool -B -i *.gif' converts all images to interlaced GIF files.

GIFTool is shareware.  Use the -info option to read the licensing information.

Two options are recommended.  You can specify them after "make clean".
make RETVALUE=yes
	This option, suggested by Sergei Chechetkin
	<csl@whale.sunbay.crimea.ua>, causes GIFTool to provide a return value
	so may be used in pipes or with programs like make(1).
make MALLOCSIZE=yes
	This option, suggested by Hidetoshi Shimokawa
	<simokawa@sat.t.u-tokyo.ac.jp>, increases the size of a malloc, to avoid
	a segmentation fault when pre-reading some images.
You can specify both options such as 'make RETVALUE=yes MALLOCSIZE=yes'.