Ori Livneh has created a nice dashboard that regularly polls the Main Pages of a few of our projects to break down the amount of JavaScript (and other static assets) that's loaded for an anonymous pageview of the Main Page:
https://ganglia.wikimedia.org/latest/?r=week&cs=&ce=&tab=v&v...
Commons currently loads more than 1MB of JavaScript. This is too much, which negatively affects performance for our end users. Some of this is on WMF -- JS code we've deployed that we can optimize. But it would also be good to get community help with auditing site JS and gadgets that are loaded by default and that can be reduced in complexity, loaded only when needed, etc.
We'll aim to provide better debugging tools to the community in future but wanted to point this out in case anyone already wants to take a closer look.
Erik