With its open source release Thursday of its Closure JavaScript tools, Google (GOOG) is starting to suggest that it may eventually become a good open source citizen. The newly released tools include a JavaScript compiler, a very broad JavaScript class library, and Java/JavaScript-friendly templates. All are released under the Apache 2.0 license, a very permissive license that essentially lets outsiders do whatever they want (rather than a viral or semi-viral license like EPL or LGPL).