Type this command to build WebKit:
WebKit/WebKitTools/Scripts/build-webkit
Use the --debug option for a debug build, which includes debugging symbols and assertions:
WebKit/WebKitTools/Scripts/build-webkit --debug
By default, build-webkit places build products in WebKit/WebKitBuild. You can specify a different build location on Mac in your Xcode preferences. On Windows, the WEBKITOUTPUTDIR environment variable can be used to set a different build products location. If you have set up a custom build location, then build-webkit will place the build products there.
A common source of build errors on Windows is Visual C++ Express forgetting the Platform SDK paths. If you have trouble building WebKit, double check that the paths you set during step 3 of the Platform SDK Installation are still there and add them again if necessary.
Don't forget that if you have any questions or problems building WebKit, feel free to get in touch!
To set a default build configuration for build-webkit and other scripts, use the set-webkit-configuration script:
WebKit/WebKitTools/Scripts/set-webkit-configuration --debug
WebKit/WebKitTools/Scripts/set-webkit-configuration --release
It's handy to put WebKit/WebKitTools/Scripts in your shell path so you can type commands like build-webkit without specifying a full path.
Once your build has finished, you can run it inside Safari.