As it is, I see no (verifiable) indication that this is an officially sanctioned giveaway. As far as I can tell, this is a random warez serial posted by a random person on the internet.
It's one of those programs that always seems to be available as a free giveaway somewhere, (much like WinX HD Converter Deluxe).
Here's a current one (Infinigeek
- says expires March 15 but the software site says March 17):WonderFox HD Video Converter Factory Pro Giveaway
Video Converter Factory website[EXPIRED NOW]
Valid until March 17, 2017 - same license key as given above so this offer here is not exclusive
Having tried it once, it's main strength lies in the average user just being able to pick an output format to suit a device without having to mess about with encoder parameters.
BTW, if you're thinking of buying it, install it, then uninstall it - they'll offer a 70% discount to change your mind
Also, if you don't want to install it, use UniExtract
to extract the NSIS installer and answer (N)o
when it prompts you to overwrite any extracted files, (otherwise you'll end up with the Japanese version - which is OK if you can read Japanese), then just run and register.