You can install all or part of Eclipse WTP in your current Eclipse.
To install only JSDT, go to "Help> Install New Software ...".
In the "Work with" section, select the Eclipse main site ( http://download.eclipse.org/releases/luna for Eclipse Luna).
Expand the "Web, XML, Java EE, and OSGi Enterprise Development" section and select "JavaScript Development Tools"
Click "Next"> to continue the installation.
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