I am using Mac OS X 10.3.9. When I was building the webkit, I got an error: /Users/work/Projects/build/libWebKitSystemInterface.a === BUILDING NATIVE TARGET dftables USING BUILD STYLE Deployment === === BUILDING NATIVE TARGET JavaScriptCore USING BUILD STYLE Deployment === CompileC /Users/work/Projects/build/JavaScriptCore.build/JavaScriptCore.build/Objects-normal/ppc/WebScriptObject.o bindings/objc/WebScriptObject.mm normal ppc objective-c++ com.apple.compilers.gcc.3_3 setenv MACOSX_DEPLOYMENT_TARGET 10.3 cd /Users/work/Projects/webkit/JavaScriptCore /usr/bin/gcc-3.3 -x objective-c++ -arch ppc -pipe -Wno-trigraphs -fno-exceptions -fno-rtti -fasm-blocks -fpascal-strings -Os -mtune=G4 -Werror -Wmissing-prototypes -Wnon-virtual-dtor -DNDEBUG -DAPPLE_CHANGES -DHAVE_CONFIG_H -Wall -W -Wcast-align -Wchar-subscripts -Wformat-security -Wmissing-format-attribute -Wpointer-arith -Wwrite-strings -Wno-format-y2k -Wno-unused-parameter -Wno-long-double -fmessage-length=0 -F/Users/work/Projects/build -I/Users/work/Projects/build/include -Iicu -I/Users/work/Projects/build/JavaScriptCore.build/JavaScriptCore.build/DerivedSources -Wp,-header-mapfile,/Users/work/Projects/build/JavaScriptCore.build/JavaScriptCore.build/JavaScriptCore.hmap -include /Users/work/Projects/build/SharedCaches/JavaScriptCorePrefix-cotkribcgonzbhcwynsiocvroabu/JavaScriptCorePrefix.h -c /Users/work/Projects/webkit/JavaScriptCore/bindings/objc/WebScriptObject.mm -o /Users/work/Projects/build/JavaScriptCore.build/JavaScriptCore.build/Objects-normal/ppc/WebScriptObject.o /Users/work/Projects/webkit/JavaScriptCore/bindings/objc/WebScriptObject.mm: In function `NSString* -[WebScriptObject stringRepresentation](WebScriptObject*, objc_selector*)': /Users/work/Projects/webkit/JavaScriptCore/bindings/objc/WebScriptObject.mm:343: warning: `NSString' may not respond to `+stringWithCString:encoding:' /Users/work/Projects/webkit/JavaScriptCore/bindings/objc/WebScriptObject.mm:343: warning: cannot find method `+stringWithCString:encoding:'; return type `id' assumed ** BUILD FAILED ** I found that +stringWithCString:encoding only available in Mac OS X 10.4 (http://developer.apple.com/documentation/Cocoa/Reference/Foundation/ObjC_cla...). Does that mean that I can only use Tiger to build WebKit? Thanks!