Do any of these resources help? https://pypi.org/project/idna/ https://www.verisign.com/en_US/channel-resources/domain-registry-products/id... On 7/1/19, 11:51 PM, "UA-discuss on behalf of Michael Casadevall" <ua-discuss-bounces@icann.org on behalf of michael@casadevall.pro> wrote: Short version: Is anyone aware of an implementation of IDNA2008 that is in the public domain or MIT/BSD licensed? Long version: During a discussion with Paul Hoffman, we were talking about the state of IDN support in at a core programming language level, and my efforts to write a yellow paper showing the full effort required to implement support for IDNs/EAIs we talked about the licensing of libidn2. Specifically, libidn2 is dual-licensed under the GPLv2/LGPLv3. This is rather problematic for implementing IDN support in many applications coded in C/C++. GPLv2 requires that an application that uses libidn be free and open source and compatible the GPLv2 licensing terms which is impossible for any propitiatory software package, or those under a free software but non-GPL compatible license such as the CDDL. LGPLv3 in theory solves this problem, but adds even more complications. LGPL allows libidn2 to linked to proprietary software but only in the form of a shared library (dll or so) file. However, LGPLv3 requires patent grants be given to any user of said library (GPLv3 section 11). This clause adds an extremely high barrier to entry in corporate environment which involves legal questions and may not be surmountable. As we want IDN support to go as far as wide as possible, the best way to accomplish that is an IDNA2008 implementation that is entirely non-embured, either under the MIT license, another weak copyleft license, or ideally in the public domain or CC-0 licenses. I searched around and came up empty but I'm hoping the list can point me in the right direction. Michael