7.1 - Changes in the Language

• The vararg system changed from the pseudo-argument arg with a table with the extra arguments to the vararg expression. (Option LUA_COMPAT_VARARG in luaconf.h.)
• There was a subtle change in the scope of the implicit variables of the for statement and for the repeat statement.
• The long string/long comment syntax ([[string]]) does not allow nesting. You can use the new syntax ([=[string]=]) in these cases. (Option LUA_COMPAT_LSTR in luaconf.h.)