Gary Litvin is a co-author (with Maria Litvin) of Be Prepared for the AP Computer Science Exam in Java, now in its fourth edition.  Maria and Gary also co-wrote C++ for You++, and more recent Java Methods A & AB: Object-Oriented Programming and Data Structures, the textbook used for AP CS courses in hundreds of schools.  Since 1999, Maria and Gary co-wrote questions for the Continental Mathematics League contests in computer science; this collection is now available in the book 250 Multiple-Choice Computer Science Questions in Java (Skylight Publishing, 2008).  Their latest book is Mathematics for the Digital Age and Programming in Python (Skylight Publishing, 2008), now in its second edition (2010).

Gary is the founder and chief technical contributor of Skylight Software, Inc.  In 1985 he developed and put on the market software products SKYLIGHTS/GX, a GUI rapid prototyping tool and HANDPRINTS, a set of routines for on-line handwritten character recognition. More recently, Gary participated in various contract software development projects, such as OCR (optical character recognition), and credit card fraud detection, and developed data analysis tools and neural networks software.

Prior to starting his own company, Gary was Director of Software at MicroTouch Systems, Inc., in Woburn, Mass. and Senior Member of Technical Staff at GTE Laboratories (now Verizon Laboratories).