I read about Poisson Rouge (Red Fish) at Imagination Soup, and immediately checked it out. I had to skip washing my windows because I got so busy playi...er, researching there.
Some simpler activities at Poisson Rouge might not interest over sixes immediately, but it's worth them exploring deeper into this site for real gems. Younger kids will enjoy just clicking or scrolling over pictures on the main page to see what activities arise! There are heaps of things to activate and interact with. You can play guitar chords, make a machine, experiment with algorisms, and sing along with the choir.
There's an English school where kids can see and hear common words in English, and similarly one in French. (École d'Anglais and École de Français.)
Explanations are in French, but there is an index of activities within. Basically the French tells you to click on anything and everything to see what will happen. Isn't that the method most of us use? You can't really go wrong by clicking on the thumbnails.
The Book Chook's favourite activities? Being able to get four little animations singing Frère Jacques as a round, composing a song on the piano and seeing the score written for me above, playing a board game (Jeu de Plateau) against the computer, and sliding my mouse over the night sky to see the constellations light up.
This is a wholesome, fun, and creative site. I think your kids would love it!