The latest version of WebKitGTK+ can be downloaded from Softpedia
WebKitGTK+, a version of the WebKit open source web engine that uses GTK+ as its user-facing frontend, is now at version 2.3.90.WebKitGTK+ is out and includes both the WebKit1 and WebKit2 APIs by default. As for the WebKit1 API, it's now in maintenance mode and the developers will continue to fix any bugs.
According to the changelog, initial touch support has been added to WebKit2, an API to create a WebKitWebView related to another one to share the same Web Process has been added, and the inspector view is now created using the same web process as the inspected page.
Check out the official announcement for a complete list of changes, updates, and new features. Users who intend to compile WebKitGTK+ have to keep in mind that it has a lot of dependencies.
Download WebKitGTK+ 2.3.90 right now from Softpedia. Remember that this is a development version and it should NOT be installed on production machines. It is intended for testing purposes only.