The public mls system is the official site of the Canadian Real Estate Association. It is the gateway to all the listings across Canada. As stated at their website the public mls website is a medium provided by REALTORS across Canada to help market properties that are listed on the mls.

Ths definition of mls is multiple listing service.

Almost all local board mls systems provide data to the public mls system to facilitate the public's search of mls listings in their particular areas and across Canada.

All people who have access to a computer have access to the public mls system in Canada. It is similar to the public mls system in the United States.

Most real estate boards in Canada (the Toronto Real Estate Board - TREB - being one of them), upload partial listing information to the public mls system on a regular basis.

It is important to know that the public mls system is for the public and only provides limited information about the particular listings. Realtors utilize their local mls system to search and find mls listings and they have access to far more details and information about a particular listing than what is available on the public mls system. The privacy act in Canada is the main reason for this.

Conclusion
The public mls system is available to everyone to use to search and see mls listed properties across Canada.