Hello, Regarding the example of using multiple XS files, as detailed here: http://search.cpan.org/dist/ExtUtils-MakeMaker/lib/ExtUtils/MakeMaker/FAQ.pod#XS
The explanation goes about calling the boot function of one module (Cool::Bar) from another module's XS (Cool::Foo). When I tried to compile such an example, I got the following error === foo.xs: In function ‘void boot_Cool__Foo(PerlInterpreter*, CV*)’: foo.xs:22: error: ‘boot_Cool__Bar’ was not declared in this scope make: *** [foo.o] Error 1 === It could be that I've done something wrong, but at least from my naive C-compiler POV, the error is correct: the function "boot_Cool__Bar" is not declared in the scope of Foo.xs/Foo.c . My work-around was to add the following forward-declaration to the file Foo.xs (at the beginning of the file, before the MODULE keyword): ==== XS(boot_Cool__Bar); ==== Then everything compiled and worked fine, as per your example. Hope this helps, -gordon