[whatwg] HTML resource packages

[timeless]

People should probably consider reading the Web Apps Widgets working
group archives (they're public) about widget packaging.

There are long discussions about zip and gzip, etc.

http://www.w3.org/TR/widgets/#zip-archive

Especially http://www.w3.org/TR/widgets/#character-sets covers character sets.

As for zip streaming / gzip streaming...
Officially Zip technically has ways to construct archives which are
painful. In practice I don't think that's a real problem (beyond that
user agents would need to ensure to fail any packages which abuse
those features).
People tend to come late to the game and say "why didn't you use
gzip". The general short answer is that gzip doesn't cover a file
container format at all, and browsers tend to already support zip. So
the cost of using zip is negligible whereas adding something else
which is messy (e.g. tar, star, pax) is painful. And if you think that
tar is well specified, I have a bridge I'd like to sell you.