From the CW-WDM MSA Group LinkedIn text provided by Nodrog a couple of days ago: 

"Industry leaders are already on board. These pioneers are rolling out CW-WDM MSA-compliant products, paving the way for the next wave of optical interconnect innovation:

 · Ayar Labs 

 · Lumentum 

 · MACOM 

 · Sivers Photonics 

 · Quantifi Photonics 

 · POET Technologies

By creating new opportunities for optical suppliers and enabling cutting-edge applications, the CW-WDM MSA is set to drive innovation across the entire optical ecosystem."

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The short list of six was selected from the 11 promoter members and 45 observer members.  https://cw-wdm.org/members/#promoters 

POET is the only member that enables the "rolling out CW-WDM MSA-compliant products" for itself and everyone else via a platform that produces superior optical engines utilizing all lasers and wave division multiplexing techniques.

To answer your question, the closest to being a "competitor", in my estimation, is Skorpios Technologies which is also an observer member of the CW-WDM-MSA. Skorpios has its own platform, FAB and tools releated to III-V materials. Its products are Direct Detect, Coherent, CPO and Lidar.  https://www.skorpiosinc.com/products-technology/tru-siph-technology-advantages/