What is your usual way of prototyping? Forget the file handoff and the email mess of sending those HTML prototypes. Collaboration with Designers is made easy in Assembla. Just check out the render button on any HTML document:
- render a file at any revision in Git, Subversion or Perforce
- get fully rendered HTML page - with CSS and JS
This makes the full-blown HTML prototype be only a commit away and you never lose it, because it is in your repository!
Learn more about collaboration here