He is the leading architect of the Lua programming language and the author of "Programming in Lua" (now in its second edition and translated to Chinese, Korean, German, and Japanese). Roberto has a M.Sc. Degree (1986) and a D.Sc. Degree (1990) in Computer Science, both from PUC-Rio. He was a visiting researcher at the University of Waterloo, (Canada, 1991), ICSI (CA, USA, 1994), GMD (Germany, 1997), and at UIUC (IL, USA, 2001/2002). As a professor at PUC-Rio, Roberto was the advisor of several students that later became influential members of the Lua community. Lately he has been developing LPEG, a novel pattern-matching package for Lua.