The Hillside Group was formed out of a workshop that GradyBooch and I called in the summer of 1993. We met in the mountains of Colorado to discuss patterns. One of the exercises we tried was using ChristopherAlexander's patterns to design an office for us all to work together. We were on the side of a hill when we did it, hence the name.
Since then, the Hillside Group has gotten incorporated, sponsored the PLoP94 conference, and planned the PLoP95 and EuroPLoP conferences.
BruceAnderson:
The Hillside Group has also sponsored and helped to run the PLoP96, PLoP97, EuroPLoP96, UP97, EuroPLoP97 and PLoP97 conferences, and the PLoPD1, PLoPD2 and PLoPD3 books.