Featured Testimonials

Kudos. I'm actually really liking ANTLR! I have a pretty darn good velocity with a rapid prototyping project I am doing in my Google 20% time. For example, I just discovered a feature in rewrite rules that does exactly what I need (referencing previous rule ASTs, p. 174 in your book). It took me about 5 minutes to get this to work and remove an ugly wart from my grammar. Hats off!
Guido van Rossum, Inventor of Python

ANTLR is an exceptionally powerful and flexible tool for parsing formal languages. At Twitter, we use it exclusively for query parsing in Twitter search. Our grammars are clean and concise, and the generated code is efficient and stable. The book is our go-to reference for ANTLR v4 -- engaging writing, clear descriptions and practical examples all in one place.
Samuel Luckenbill, Senior Manager of Search Infrastructure, Twitter, inc.

Just wanted to take the opportunity to say thanks. ANTLR is a BIG improvement over yacc/lex, and your support for it most commendable. Managed to get my tired old brain around it in a day. Nice work!
Brad Cox, Inventor of Objective-C


I absolutely adore the parse tree listener feature of ANTLR v4! Almost no grammar actions left! Kudos.
Kay Röpke

OMFG - i've been programming now for many years now at Google, on Wall Street, some embedded stuff, the whole shebang. Nothing i've seen is as mind blowing as ANTLR 4. I mean wow ! I've been playing with it for about 2 hours with only vague memories of the dragon book from the Compilers course in college 15 years ago and my grammar is working ! And i've only been reading the ANTLR 4 ref book for like 20 minutes ! it's such a pleasure to come across something so powerful that just works and is instantly understandable. So far it's power seems only to be exceeded by it's simplicity and elegance. Bravo sir !
Clive Saha

I've been using Antlr 4 a bit and find it pretty amazing, even compared with Antlr 3. It handles direct left recursions flawlessly. I've been continually surprized by the way it handles erroneous input. I've never seen anything recover so well.
Tony Passera

A quick thank-you note for writing ANTLR 4! I've used it with the C# target to create a simple but quite powerful scripting language for a client I'm consulting. It was very easy to get into (because of your book and YouTube video) and the generated listener/visitor patterns work extremely well for my purpose. Long story short, in the span of about a week, I was able to not just design the scripting language from scratch but also implement an IL bytecode compiler for it, so everything runs right on the CLR (and Mono runtime). In fact, it’s a proper .NET language!
Claus Topholt