"Any sufficiently complicated web application contains an ad-hoc, informally-specified, bug-ridden, slow implementation of half of the browser's native behaviou

"Any sufficiently complicated web application contains an ad-hoc, informally-specified, bug-ridden, slow implementation of half of the browser's native behaviour." To which I would add the adjectives outdated and brittle. It is possible, with care, to replicate almost any UX behaviour that is native to the browser or its underlying platform, but: 1. When the browser or platform changes, the "greenspunned" behaviour does not keep up, so you are either stuck with outdated behaviour, or you have to go back and update your web app to keep up. 2. Most of the high-fidelity implementations rely on a tottering jenga pile of hacks and workarounds that break in unpredictable ways when changes are made to the site's appearance (e.g. a rebranding exercise) or to the browser's underlying behaviour. I've become very conservative about doing anything like this myself. I have extreme difficulty coming up with business justification for reïmplementing standard behaviour. It is not my job to make scroll bars, buttons that depress when you mouse down, and especially, custom text input fields that—thanks to my meddling—don't support standard behaviour like native spell checking, copy and paste. Now please excuse me, I've lined up a row of Geritol and Jack Daniel's ("Gerry & Jack's") shots, and it's time for a drink.