Roberto Ierusalimschy is an associate professor of informatics at PUC-Rio (Pontifical University in Rio de Janeiro). He is the leading architect of the Lua programming language and the author of Programming in Lua (ISBN 85-903798-1-7) and Programming in Lua, Second Edition (ISBN 85-903798-2-5). He is also responsible for introducing Parsing Expression Grammars as a formalism over ad-hoc regular expression structures.