I first heard about Jeffrey Friedl from his rather good web-based
Japanese-English Dictionary, which helped me get through two years of Japanese language class. The domain name for that site belies his more common notoriety — he is an expert on
regular expressions (or
regexes for short).
Mastering Regular Expressions is
the book for regexes; nobody else even comes close. I have a copy on my shelf, and it's been an invaluable resource for work and play. Yes, I play with regexes, don't look at me like that.
Now, you may be wondering why a renowned author of a famous programming book is doing making a Japanese-English dictionary. To answer this, you need only look at the dedication for his book: 文枝, Fumie. His wife is Japanese.
Jeffrey Friedl, you are my idol. :-D