It includes use of PHP namespaces (therefore requires php 5.3+).
It also corrects that annoying hack that was required to allow any characters in decoration argument values. So now you can write, properly:
$simplewiki->parser()->argchars('(?s:.)');//include any characters including linefeeds
Note that the '?s:' (ie 'including linefeeds') is required.
Also note that these two changes mean that version 1.1 is not compatible with version 1.0, so some integration effort will be required.
simplewiki has been used pretty intensively on publiccommons.ca
, and I haven't had any problems with it for many months, now, so it appears to be very stable.