I was thinking of using the PostScript backend of Cairo for getting complex text to render properly in the PS outputs from Firefox, and hence I downloaded the latest source from CVS. ..and guess what - it has been already implemented!! Mozilla can now print Indic properly. Check out this Postscript file obtained from Firefox (using print to file).
I supplied the following arguments to the configure script:
--prefix=/opt --enable-default-toolkit=cairo-gtk2 --enable-cairo --enable-pango --enable-application=browser --enable-xprint
…and in case anyone is wondering how I figured out that the magic is being done by cairo - here are the first few lines in the postscript file:
%%Creator: cairo (http://cairographics.org)
%%CreationDate: Sat Sep 9 12:28:52 2006
%%BoundingBox: 0 0 595 841