Tip: Hover information shows HTML source?

Eclipse uses an embedded browser control to display nicely formatted documentation and hover information. Apparently Ubuntu 14.04.x comes with libwebkitgtk-3.0.0 pre-installed and this is NOT compatible with SWT.

sudo apt-get install libwebkitgtk-1.0-0 is required.

Also, make sure that the browser is enabled in the preferences.