Java 5 or higher. You need the JDK, not only the JRE.

To verify please execute the following command in your shell:

java -version

Download from http://qooxdoo-contrib.sourceforge.net/downloads/qwt/releases/qwt-0.2.0.zip

• Unzip the archive, it extract to a folder qwt-0.2.0

• Add qwt-0.2.0/bin to your path

• Test you setup: open a shell and run

  mvn qx:help

  QWT should print a usage message.

That’s it, QWT is now installed.

Read Getting Started, Uninstall or Upgrade