I was thinking of export options for NoteWritey, when I remembered that TW 5.1.23 will have a new zip plugin update. In fact, it actually works now in 5.1.22 if you drag and drop in the jszip plugin from the prerelease. Well, I think it does.
As you may know, when you try to export multiple tiddlers in the "tid" format, you only get one tiddler as output. With the following code, you can export multiple tiddlers packed into a zip file which you can then extract using your favorite zip manager.
I'm sure over time people will come up with much more clever uses for the zip plugin, but in the meantime, here's a first stab. The macro takes a filter, and output name, and title for the button.
\define ziptid(filter: "[all[tiddlers]]" , output: "tiddlers.zip" , title:"Make Zip")
<$button> $title$
<$vars ziptid="$:/temp/zip">
<$action-sendmessage $message="tm-zip-create" $param=<<ziptid>>/>
<$vars sys="$:/" >
<$list filter="""$filter$""">
<$vars fname={{{[<currentTiddler>split<sys>join[_]split[/]join[_]addsuffix[.tid]] }}} >
<$action-sendmessage $message="tm-zip-render-file" $param=<<ziptid>> filename=<<fname>> tiddler=<<currentTiddler>> template="$:/core/templates/tid-tiddler" mode="block" output="text/plain"/>
</$vars>
</$list>
</$vars>
<$action-sendmessage $message="tm-zip-download" $param=<<ziptid>> filename="""$output$"""/>
</$vars>
</$button>
\end
<<ziptid "[tag[Learning]]" "Learning.zip" "Zip Learning">>