(CDT) Perl interpreter-based threads
Since Perl 5.8, thread programming has been available using a model called interpreter threads which provides a new Perl interpreter for each thread, and, by default, results in no data or state information being shared between threads. (Prior to Perl 5.8, 5005threads was available through the "Thread.pm" API. This threading model has been deprecated, and was removed as of Perl 5.10.0.)