[mascarenhas]

Check LuaRocks (http://luarocks.org), a package manager/installer for Lua, it makes deployment of C extensions much easier (no root access required).

About deployed Lua webapps, there's http://www.wowprogramming.com/, using Sputnik (http://sputnik.freewisdom.org) on top of the Kepler (http://www.keplerproject.org) stack. The forums are Sputnik extensions.