Dejal Systems (http://www.dejal.com/simon/) has introduced Simon Express and Simon Free, new editions of the server monitoring tool for Mac OS X (10.5 and higher), especially for the Mac App Store.

These editions check web pages, FTP and DNS servers for changes or failures, and notify you via sound, speech, and other means. They're streamlined editions of the full Simon application, which supports many more services, filters, notifiers and reports.

There are now three editions of Simon: Simon: the standard edition, sold directly from the Dejal website; Simon Express: a paid edition, sold on the Mac App Store; and Simon Free: a free edition, available on the Mac App Store.

The standard edition of Simon is unchanged; it includes all the same features as before, and is sold in four license levels: Bronze: this enables up to 15 active test configurations; Silver: this enables up to 40 active test configurations; Gold: this enables up to 100 active test configurations; and Platinum: this enables an unlimited number of test configurations. Pricing starts at US$49.

The Mac App Store editions, Simon Express and Simon Free, on the other hand, have a more streamlined feature set. They only have a few of the plug-ins that provide the services, filters and notifiers. They also don't include editor windows for services, filters and notifiers, and don't include the reports feature.

Simon Express ($59.99) has no limitation on the number of test configurations. It's designed for webmasters and others who want to monitor hundreds of websites.

Simon Free is the same as Simon Express, except that it's limited to five active test configurations. It's designed for people who just want to monitor their own site and a few others.