Welcome to the eighth issue of The Left Fold, a weekly programming news and article digest.

Representing Chess Positions : options and the trade-offs.

Winning the 2K Bot Prize with a Long-Term Memory Database using SQLite : discusses several parts of an AI first-person-shooter player.

Regular Expression Matching: the Virtual Machine Approach : explores several different ways to implement regular expressions using a virtual machine, with code.

Ruby Draft Specification : to be submitted to ISO for standardization. This is an endeavor separate from RubySpec . See also discussion on ruby-core@ .

The much-delayed ECMAScript 5 (JavaScript) specification was released:

Sun's "Project Lambda" to add first-class functions, function types, and lambda expressions to Java kicked off this past week:

Scaling to efficiently process large datasets: a high-level overview from Facebook and another from Google.

Tuning Concurrent Clojure: finds it's not the algorithms, it's the JVM options and type hints.

Optimizing Common Lisp: demonstrates how to annotate Common Lisp code for performance and how the SBCL compiler helps.

How I Learned to Stop Worrying and Love Erlang's Process Dictionary: using a mutable datastructure in a purely functional context.