I wasn't able to find information about what license the WebKit source is under on the website. While I understand that this information would be in a pulled source tree, including this information on a project's site is somewhat standard and allows people to check the license before potentially tainting themselves with source.
Different parts of the source is under licences afaik. Apple specific portions of the libraries are under a new style BSD-like license, and the rest is under LGPL. (As a whole, I believe the entire library is LGPLed) Could explain why.
Confirmed, this is not an easy thing to do though.
The sidebar at http://webkit.org now says: "WebKit is open source software with portions licensed under the LGPL and BSD licenses. Complete license and copyright information can be found within the code."