I've pushed a new slideshow (S9) gem  , that is, v2.3.0. What's new?
I've added support for Mediawiki markup - thanks to the wikicloth
 gem. Use the extensions .mediawiki, .wiki or .mw, for example, to
write your slideshows in Mediawiki.
Note, the wikicloth gem is optional. To use it install it "manually"
$ gem install wikicloth
I've also "downgraded" Textile support to optional due to
installation issues. Starting w/ version v2.3.0 to use Textile install
the RedCloth Textile library "manually" first e.g. issue:
$ gem install RedCloth
Lastly I've added some more sample plugins/helpers, that is, tables
(left, right, etc.)  and snippets (help, etc.) . To install all
$ slideshow install plugins # or install plugins/helpers
$ slideshow install tables
$ slideshow install snippets
That's it. Questions? Comments? Cheers.