Java 1.4 went EOL in February 2013.
Tools that used to support it (like an 8 year old version of WTP) are also therefore EOL.
I was doing this activity, for Apache XercesJ XML Schema 1.1 project, that uses Eclipse XPath 2.0 processor from Eclipse WTP
(from a branch, that supports min JDK 1.4). XercesJ XML Schema 1.1 project supports min JDK 1.4, hence it needs a min Java 1.4 based XPath 2.0 processor. I personally, would wish that XercesJ should support something like min JDK 1.8.
I'd suggest opening an Eclipse Bugzilla if you need something from the webmasters or the WTP PMC.