LuaSandbox provides a sandboxed environment which differs in some ways from standard Lua 5.1.
pcall() and xpcall() cannot catch certain errors, particularly timeout errors.
tostring() does not include pointer addresses.
string.match() has been patched to limit the recursion depth and to periodically check for a timeout.
math.random() and math.randomseed() are replaced with versions that don't share state with PHP's rand().
The Lua 5.2 __pairs and __ipairs metamethods are supported by pairs() and ipairs().