I really like this demo, but it reliably crashes a mid 2012 macbook pro with lion, both on firefox and safari (the older version of the demo was the same).

Now, reading the other comments, i wonder if there are any tools that help with diagnosing device capabilities? I don't have high hopes of integrating anything WebGL related in my projects due to these problems, so how can you make sure that WebGL code will work across devices?

Edit: How can you make sure you notice when it's not working?