One inherent advantage TurboGears has over monolithic frameworks is in its ability to exploit the best in already existing and supported component projects rather than having to duplicate their efforts. A consequence of this ability is the ease with which components can be swapped for alternative choices when preferred by the developer.
Installing one or more of these options into your library is very simple. It is possible to call upon an alternate component on an as needed basis, for example for just a single template reference. Or, Quickstart Templates can allow for rapid configuration of a new project which has an alternate component as its new default.
You can find most of TurboGears alternative components at http://www.turbogears.org/cogbin/