License to use WinVN
The authors of WinVN have placed it in the public domain. This means you can use it free of charge for any purpose you like, with no conditions being placed on its use by us. The source code is also available free of charge, under the same [un]conditions.
You have our permission to modify, redistribute, hoard, or even sell WinVN in its executable or source form. You don't have to pay us anything. If you do sell WinVN, though, we'd appreciate it if you'd provide your own support. The support load for WinVN is already quite substantial, and the WinVN developers work as unpaid volunteers (except in the case of supporting their own in-house users).
[from the on-line help]