Scratch

Scratch is a new programming language that makes it easy to create your own interactive stories, animations, games, music, and art -- and share your creations on the web.
Scratch is designed to help young people (ages 8 and up) develop 21st century learning skills. As they create Scratch projects, young people learn important mathematical and computational ideas, while also gaining a deeper understanding of the process of design.
Scratch is available free of charge.

I've never tried this tool but I will because it seems really interesting.

Hot Potatoes

This is probably the best known software that allows users create interactive exercises. It is the one I use more often with my students not only because they actually enjoy doing this type of exercises but also because I have feedback on their performance.

The Hot Potatoes software includes six applications: multiple-choice, short-answer, jumbled-sentence, crossword, matching/ordering and gap-filling. Hot Potatoes is free of charge for those working for publicly-funded non-profit-making educational institutions, who make their pages available on the web.
You have to register to use it.

http://hotpot.uvic.ca/