The Connectivity Standards Alliance (CSA), formerly the Zigbee Alliance, is a group of companies that maintain and publish the Zigbee standard and the soon to be Matter standard. The name Zigbee is a registered trademark of this group, and is not a single technical standard. The organization publishes application profiles that allow multiple OEM vendors to create interoperable products. The relationship between IEEE 802.15.4 and Zigbee is similar to that between IEEE 802.11 and the Wi-Fi Alliance. Over the years, the Alliance's membership has grown to over 500 companies, including the likes of Comcast, Ikea, Legrand, Samsung SmartThings, and Amazon. The Zigbee Alliance has three levels of membership: adopter, participant, and promoter. The adopter members are allowed access to completed Zigbee specifications and standards, and the participant members have voting rights, play a role in Zigbee development, and have early access to specifications and standards for product development. The requirements for membership in the Zigbee Alliance cause problems for free-software developers because the annual fee conflicts with the GNU General Public Licence. The...