The Green Building was lit up last Friday with altering patterns of “GNU” and “30” in honor of the 30th anniversary of GNU, a free Unix-like operating system. Rachel E. Aviles—The Tech May. 9, 2016 Facebook Twitter Reddit Print The Green Building was lit up last Friday with altering patterns of “GNU” and “30” in honor of the 30th anniversary of GNU, a free Unix-like operating system. Rachel E. Aviles—The Tech