I have been looking for open source curricula for middle school math and science, specifically for Ontario, and the pickings are slim.
I came across this site from British Columbia. It is not a complete curriculum, but it has a few select modules for various subjects and grades. The Centre for Education and Mathematics and Computing (CEMC) recently released a grade 7 and 8 math curriculum. They also have available content for Advanced Functions, Pre-Calculus, and Calculus and Vectors. Unfortunately these two sites were the only ones that I found that directly matched my curriculum.
There are also some good options beyond Ontario and Canada based curriculum. Below you will find a list of some of the more popular options (focusing on k12 education).
New Jersey Centre for Teaching and Learning
Illustrative Mathematics and Open Up Resources
Specifically Online Textbooks:
openstax CNX – Mostly high school math and science textbooks with a few extras
BC Open Ed – Textbooks in many subject areas
Curated Databases:
Merlot – Curated sources across all disciplines
OER Commons – Curated sources across all disciplies
I am sure that I have missed some essentials that should be on this list. But it is late at night and I have been working all day, and my brain is in back-to-school mode. Please let me know what I am missing.