Quasar
CodeBrain's free applet is a multi-layer animation applet with amazing versatility and range, sound support, simple setup, and a very small, fast, single .class file.

QGoo
Stretch and smear your images with this goo-ing applet. Loads any web image; easy click and drag controls for goo-ing.

QuickJava
A suite of four free text applets, with a free configuration wizard included!

quickserv
QuickServ is a java applet pre-loader; it pre-loads the pages which are linked from your Web site while a user is viewing your page.

QuizShow
Quiz Show is a trivia applet that is configurable in every way from the questions and answers to the phrases from the host and buzzer sounds.

Quote
Sun Microsystems' original Quote applet displays a series of text quotes. Source included.

Quoter
The free Quoter applet takes a file of quotes (separated by Carriage Returns), and displays one at random in the applet window.

Queens vs Knights
The object of the game is to place the 4 Queens and 4 Knights in positions that do not threaten each other. Source included.