No-Library (pure JS), HTML, CSS, JavaScript
Underscore 1.4.4, HTML, CSS, JavaScript
jQuery 1.6.4, HTML, CSS, JavaScript
jQuery 1.7.2, HTML, CSS, JavaScript
Subscribe calls itself when triying to "clean" the subscribed observable. The alert sends twice.
https://groups.google.com/forum/#!topic/knockoutjs/P3FM8CgeR-w/discussion