1. Not quite sure. I've only used PhantomJS via Selenium Ghost Driver. From that usage they're similar. The main difference is that my driver uses only Java so under the hood the JRE is launching WebKit through JNI and everything runs in the same JRE process.
2. Current WebKit version depends on the JRE used. Oracle Java 1.8.0_45 has WebKit version 537.44.
3. Java maintainers will update WebKit periodically, including within a major version. E.g., here they update WebKit for the 1.8.0_60 JRE: http://openjdk.java.net/jeps/239 ... Other than that I'm not sure.
2. Current WebKit version depends on the JRE used. Oracle Java 1.8.0_45 has WebKit version 537.44.
3. Java maintainers will update WebKit periodically, including within a major version. E.g., here they update WebKit for the 1.8.0_60 JRE: http://openjdk.java.net/jeps/239 ... Other than that I'm not sure.