Reporting this issue on behalf of the Gentoo licenses team. It has been brought to our attention that nmap-7.90 and later is distributed under updated license terms. We see several clauses in version 0.92 of the Nmap Public Source License as problematic, to the point where we can no longer consider it as a FLOSS license. Therefore, it is license-masked, i.e., with the default distro-wide settings, Gentoo users won't be able to install the latest version of nmap.

In particular:

• In section 0 (Preamble): "Proprietary software companies wishing to use or incorporate Covered Software within their programs must contact Licensor to purchase a separate license."
  This won't allow "proprietary software companies" to use or incorporate the software within their programs (i.e., create a derivative work), even if the resulting work was distributed under a free software license. Essentially this is a non-commercial restriction and as such directly violates the Open Source Definition, section 6 "No discrimination against fields of endeavor".
• In section 2 (General Terms): "In addition, you agree to the terms of this License by clicking the Accept button or downloading the software."
  This type of language is typically found in an EULA but not in a FLOSS license. If I download the software from a third party (like Github or a distro mirror), I won't enter into any contract with either Insecure.Com LLC or the third party. Therefore nothing forces me to accept the license unless I would do any actions (like redistributing) that are covered by copyright law. Also, in the typical case, I won't even have the chance to read the license before downloading.
• In section 3 (Derivative Works): "To avoid any misunderstandings, we consider software to constitute a 'derivative work' of Covered Software for the purposes of this license if it does any of the following: [...] Reads or includes Covered Software data files, such as nmap-os-db or nmap-service-probes."
  We're aware that this point existed in previous versions of the license, but we still find it somewhat problematic. For example, it would make GNU coreutils a derived work of nmap because its programs can read those files, e.g., "cat /usr/share/nmap/nmap-os-db".

Gentoo bug: https://bugs.gentoo.org/749390
Debian bug: https://bugs.debian.org/972216
Guix discussion: https://lists.gnu.org/archive/html/guix-devel/2020-10/msg00227.html