You can work on a TiddlyWiki file in Dropbox and publish a URL that anyone can use to see a read-only view of the file.
https://www.dropbox.com/s/<gobbledegook>/mywiki.html
https://dl.dropboxusercontent.com/s/<gobbledegook>/mywiki.html
The result is a "secret" URL that you can send to other people to enable them to see the wiki.
Enter a generated URL here and you can copy and paste the secret URL:
https://dl.dropboxusercontent.com/s/<gobbledegook>/mywiki.html (open)