Finally I have time to write here some more about all the events that took place during Firefox’s 5'th anniversary. Thanks to Mozilla Europe we had a very delicious cake with a unique design. Here it is:
 
Besides the cake, as you can see we had cookies, many kinds of sweets, balloons, whistles and of course some merchandise:

After the cake-part we had 2 special sessions with talks and demonstrations and a game: "Who creates the Bulgarian web?". Here you can see some more pictures:

Slides

Here are the slides from my first talk, during this event: