Modules which purport to offer a "stateful" version of CGI:

• Continuity (7 ++s, last updated Jul 2014, first released Oct 2004)
  • leverages the Coro module, which implements coroutines
• CGI::MxScreen (last updated Oct 2004, first released Apr 2001)
• CGI::SecureState (last updated Jan 2003, first released Jan 2001)