Unfortunately, the SecureZIP 'Command Line for Windows Desktop' is not included in the free offer.
Will ZTree integration require the command line version ?

Below, quoted from:

SecureZIP Standard Version 11 - Review date: 04.24.07

<http://www.pcmag.com/article2/0,1895,2121158,00.asp>

" SecureZIP handles all standard ZIP management tasks and raises the security bar by allowing use of public-key cryptography. It integrates with Outlook to zip and encrypt e-mail attachments and even e-mail messages automatically. PKware has cut the price from $99.95 to $29.95 (the same as WinZip's standard edition), but for a limited time, you can get SecureZIP without paying a penny. Todd McLees, marketing VP for PKware, explained that the company wants to "make SecureZIP available to millions of users for free." An end date for this offer hasn't been set. "We want millions of users to download it before that conversation even occurs," McLees says. Still, I'd suggest you get your free copy right away. "

SecureZIP for Windows -- with links to current reviews:

http://securezip.com/