Dejal Simon is the essential site monitoring tool for Mac OS X. It checks web pages, FTP and DNS servers, local or remote ports, and other services for changes or failures, and notifies you via e-mail, sound, speech, or HTML reports.

Services include Web (HTTP), FTP files and directory listings, DNS, Ping servers, watch a local Application, capture periodic Screenshots, watch for System Log Errors, and more. Plus, you can easily add your own services via custom port connections, AppleScripts, shell scripts, or Perl, PHP, Python, etc.