WebKit is BSD but has sub-modules with LGPL code (specifically WebCore, JavaScriptCore, and WTF).
Ultralight is not WebKit (we have a totally different API and use our own renderer, compositor, and event-management code) but we do use a fork of WebCore and JavaScriptCore.
Our fork of WebCore is available under LGPL here: https://github.com/ultralight-ux/WebCore