I am also a Join.Me user and I would love to be able to edit my presentations with Camtasia. None of the free converters I've tried have worked, so I'm just out of luck.
If actually being able to edit those files is too big a challenge, could you at least provide a converter that would put the file into a format you CAN edit?
Thanks in advance for giving this your consideration.
Round Rock, TX
From Wikipedia: WebM is a media file format. It is primarily intended to offer a royalty-free alternative to use in the HTML5 video and the HTML5 audio tags. It has a sister project WebP for images. The development of the format is sponsored by Google, and the corresponding software is distributed under a BSD license.