I have a nice, but very irrelevant story about potion.<p>After EuRuKo 2009, we were standing at the gate on the airport of Krakow, close to boarding time. why had just disappeared and so he was the topic for our group and one of us started to lament that he wanted to have a look at potion but it had just disappeared before he could download it.<p>Suddenly, Matz appeared, waiting for his plane going from the next gate. Matz loves programming languages and he had a copy on his notebook. So there we were, in Krakow, scrambling to find a USB stick in our bags to get a copy of potion while our planes were being boarded.<p>Some people collect wine, others collect programming languages.