Full Description} Hardware is more complex than software from an intellectual property perspective, and this makes developing an open hardware licence, especially a copyleft/reciprocal open hardware licence, particularly challenging. The CERN OHL has been designed to work with as wide a range of hardware as possible, from artistic works, through mechanical devised, to circuit board layouts and, more particularly to software, microprocessor cores and even FPGAs and ASICs. At the same time, we recognise that hardware is a different domain from software, and that it is a mistake to assume that lessons learned in the software domain can automatically be applied to open hardware.

We have listened to the concerns of many users and potential users of the CERN OHL, and have produced a radical redraft of the licence which aims to:

be concise and clear; be appropriate for a wide range of different use cases in fields of use (such as microprocessor cores, FPGAs and ASICs); be appropriate for a wide range of users, from not-for-profits through to commercial organisations; be compatible, so far as possible with other licences like GPLv3 and TAPR; be easy to use; discourage licence proliferation; encourage compliance as the main outcome of enforcement; maximise the availability of open hardware designs to the public; maintain the same spirit as the previous versions of the CERN OHL; allow for strong- and weak-reciprocal licensing models, as well as permissive models.

The new version 2, in its three variants - strong, weak and permissive, is the culmination of significant drafting effort with the input of a wide range of users and potential users of open hardware licensing.

This talk introduces some of the key concepts in the CERN-OHLv2, explains its evolution from previous versions, and aims to explain how it can best be applied to a number of different types of hardware.