Mine is driven from a plaintext events.txt file, and produces an ics link that works on a corporate massively popular wildly functional and reliable web based calendar application from a silly Mountain View tech startup that shall not be named lest we have to hear how evil they are, and the ics file probably also works in, whatever else you use.  I've dawned my asbestos undergarment and am ready to hear how bad my calendar element is from others (who will be implicitly volunteering to write a better one).

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