What does H5YR mean?
It means High 5, You Rock!
Where did #h5yr come from?
Short answer: Alexander Kjerulf
As Morten Christensen said...
"One of the big highlights of Codegarden '10 was the speech by Chief Happiness Officer Alexander Kjerulf about happiness at work. He really got everybody pumped for the conference and it really set the mood for the remaining days. There were literally "High Fives" and people shouting "Your Rock!" throughout the venue (and now on twitter #h5yr)."
"Personally, I think that the "High Five, You Rock" term is a really great way of saying that various contributions are really appreciated. And it seems that people in the community keep using the term both on the forums and on twitter. Not surprisingly, because the Umbraco community really does Rock!"
Read Morten's complete blog post and get a free High5 t-shirt design.