Where to place JavaScript in an HTML file?

Where to place JavaScript in an HTML file?

Say I have a fairly hefty JavaScript file, packed down to roughly 100kb or so. By file I mean it’s an external file that would be linked in via

CSS

A little bit off-topic, but... Put stylesheets at the top.

While researching performance at Yahoo!, we discovered that moving stylesheets to the document HEAD makes pages appear to be loading faster. This is because putting stylesheets in the HEAD allows the page to render progressively. More...

Further reading

Yahoo have released a really cool guide that lists best practices to speed up a website. Definitely worth reading:
https://developer.yahoo.com/performance/rules.html