Below is a summary of the major Zigbee silicon vendors, and the companies that make modules using their chips. There are others, but these are the majors. If you notice major missing items or errors, please let me know here.

Some of the module makers only offer legacy Zigbee products, having migrated primarily to BLE, although much of this is marketing, as many of the products will happily run Zigbee apps.

There are many many domestic Chinese module makes that are not listed here, mostly BLE/WiFi focussed.

Zigbee silicon vendors

Broadcom - Don’t publish much information on their offerings aside from headline features. Only deal with very large customers.

Infineon* - Despite buying Cypress for EUR9 billion in 2019 - who bought Broadcom’s wireless IoT business (WiFi/Bluetooth/Zigbee) for $550 million in 2016 - Infineon seem to only offer WiFi/Bluetooth solutions these days.

Microchip - To get access to BitCloud SDK, documents and reference application, the customer must contact Microchip’s local sales office or an Embedded Solutions Engineer (FAE) and submit a NSCAR (Non-Standard Customer Action Request). NSCAR may request customer information and project details

onsemi - Had some solutions, but seem to have discontinued. More focussed on ultra low-power BLE.

Zigbee module makers

Nordic and Silicon Devices are clearly most popular