Are you talking about a downloaded empty.html or a downloaded version of tiddlywiki.com
TW.com contains all translated interface languages. So your users may need only one or 2 of them.
As mentioned already, you can create
IMO at the moment it doesn't make sense to compress the core js code. ... I doubt it ever will.
* A well designed server will send a compressed version over the wire, to the browser. So web traffic will be less, than the actual file size.
* 621kByte sent 2100kByte file size ... tiddlywiki.com.html
* 187kByte sent 892kByte file size ... empty.html
* In my opinion, the advantage to have readable source code, outweights the win of less disk space.
* Harddisk space is cheap.
* Maintaining a compressed TW is not cheap.
just my 2 cents