Thanks for reaching out to us, Bill.
You are absolutely correct - standard browsers to now support .avi/.mkv files. IE is required as it will by default use the local video player such as Windows Media Player. This is completely normal, and not a limitation of DriveHQ/CameraFTP, but rather of web browsers.
Please let us know if you have any other questions.
Best,
DriveHQ Support
www.DriveHQ.com