The only thing you'll always need to make PollXT working is the component. The component contains all the core functionality, to maintain polls in the backend and to display the poll on the frontend. The component is usually called com_pollxt_. Hence the current component is com_pollxt_120RC2.
The component obviously is only able to display the polls and results in the main area of your mambo site. Like the standard poll delivered with mambo, you probably want to display the polls and/or results in the module, on the left or right border. If you plan to do that you have to install the module in addition to the component. The module is called similar to the component mod_pollxt_. Please always make sure, that the releases of module and component are similar.
The Poll-List Module
This is another optional module, to be displayed in the left or right border. It displays a small list of available polls and links to them. It can be used if you want to give your users access to the Polls regardless where they are currently navigating on the page. You could achieve the same effect by creating menu entries for each poll, but the module is of course much simpler. It requires the component, but is independent of other modules. It is called Please always make sure, that the releases of module and component are similar.
The Administrator Module
The administrator module is not used to display something on the frontend, it is just a small addition for the administrator in the administration backend. It includes a tab on the homepage of the administration view, to quickly your polls for maintenance, without navigating through the menu. The administrator module is called mod_pollxtadmin_. The same constraints as above apply to this module. It requires the component to be installed with the same release.
If your using mambelfish, to translate the contents of your Site, you probably want to translate your XT-Polls, too. To do so, you have to extract the mambelfish support files to \administrator\components\com_mambelfish\contentelements. After that the PollXT-elements will show up in the mambelfish translation screen.