This example from the Beamer distribution shows the foils emulation. Slides written for the FoilTeX class are typeset by Beamer's beamerfoils compatibility layer, and each page is labelled as a Beamer emulation of FoilTeX. The two-frame sample, with title by Till Tantau, is for those who have old foils sources and want to move them to Beamer.
Shared under the GNU General Public License v2.0 or later. All credit to Vedran Miletić, Till Tantau, Louis Stuart; the licence comes with the project's files.