In Gentoo Prefix we go by Apple's convention to give modules the .bundle extension. http://developer.apple.com/documentation/DeveloperTools/Conceptual/XcodeBuildSystem/500-Linking/bs_linking.html (Above link was removed by Apple, the link below contains a copy: http://disanji.net/iOS_Doc/#documentation/DeveloperTools/Conceptual/XcodeBuildSystem/500-Linking/bs_linking.html, in case it disappears also, the relevant quote: Bundle. Bundles are executable files that can be loaded at runtime by other products. Plug-ins are implemented using bundles. The term bundle in this context refers to the binary itself, not to a structured hierarchy. Bundles have the .bundle extension; for example, MyBundle.bundle.) --- libltdl/m4/libtool.m4 +++ libltdl/m4/libtool.m4 @@ -2271,7 +2271,7 @@ soname_spec='${libname}${release}${major}$shared_ext' shlibpath_overrides_runpath=yes shlibpath_var=DYLD_LIBRARY_PATH - shrext_cmds='`test .$module = .yes && echo .so || echo .dylib`' + shrext_cmds='`test .$module = .yes && echo .bundle || echo .dylib`' m4_if([$1], [],[ sys_lib_search_path_spec="$sys_lib_search_path_spec /usr/local/lib"]) sys_lib_dlsearch_path_spec='/usr/local/lib /lib /usr/lib'