Opera help 2004 – 2013
The help pages that shipped with Opera and lived on help.opera.com: one copy of every page, taken from the most recent version that had it.
Opera for computers
The built-in help of Opera 8 to Opera 12: tabs, Speed Dial, Opera Mail, Unite, Link, Turbo, settings and keyboard shortcuts.
Opera Mini
Installing and using the Java browser on ordinary phones.
Opera Mobile
The help of Opera for Symbian phones (Nokia, Sony Ericsson, Sendo).