You may have read about Rodinal on internet forums, but had trouble finding it in Canada. That’s because it’s not sold under that name here – you want Blazinal. In some places it’s also called Adonal, so if you’ve been looking for that, this is the exact same thing, from the same factory.
So what is Rodinal? It’s a Black & White film developer that’s very popular with enthusiasts. You dilute it with large amounts of water, typically using ratios like 1+25, 1+50 or 1+100, so a bottle of this will last you for many, many rolls. And Rodinal/Blazinal is well known for having an incredibly long shelf life too, so you don’t have to worry about hurrying to develop all those rolls – if you search up “Rodinal shelf life” one of the first results has the telling line “Rodinal will outlive the shelf”.
Because you can dilute it with so much water, Rodinal/Blazinal is the perfect developer for doing stand development, and in fact, most stand development tutorials specifically tell you to use Rodinal, usually at a 1+100 dilution.