Browser load and JavaScript research

Very {Draft}. Please edit mercilessly.


 * Rough notes on Browser load concerns, and Clientside-JavaScript (?) questions.


 * Please add: Things that might be good to investigate now, and Specific metrics (time? memory?) we should track over the long-term. (or pointers, if we're already are doing this somewhere.)

Background
Over the years, and recently in person at Wikimania, I've heard comments that all the new (and accumulated old) tools/extensions/gadgets/etc, were making the client-side impact quite heavy, and the site more frustrating to use. Particularly for users with older hardware, or restricted corporate software-setups (old browsers).

Questions and Ideas for things to investigate or monitor

 * What preferences cause the most page-load increase?
 * What gadgets cause the most page-load increase?
 * What extensions cause the most page-load increase?
 * What lines in site.js cause the most page-load increase?
 * What mediawiki-core features cause the most page-load increase?


 * What are average page-loads for:
 * anon user
 * logged-in user, with default preferences
 * logged-in user, with the 10 most popular Gadgets enabled


 * How does that change, given broadband-connection, vs erratic or lowbandwidth-connection?


 * Why do some sites (like Trello) cause the browser to become sluggish when multiple tabs to it are open, and are we avoiding those problems?

Desired outcomes

 * Metrics. (bosses love metrics)
 * Shiny graphs. (users love plummet/soaring graphs)
 * long-term tracking.  (devs love tracking)
 * devs fixing the worst culprits. (priorities)
 * better understanding for everyone, technical and non. (What we're here for)
 * ponies.  (tradition)