Here is the context that makes these features not seem ad hoc: http://www.infoq.com/interviews/ecmascript-5-caja-retrofitting-security http://www.infoq.com/int

Here is the context that makes these features not seem ad hoc: http://www.infoq.com/interviews/ecmascript-5-caja-retrofitting-security http://www.infoq.com/interviews/ecmascript-5-caja-retrofitti... Many of the additions (including object.freeze) and changes were made for the purpose of making JavaScript usable as an object capability language. Mark Miller explains the background and some of the changes in the video linked above.