This looks great! I haven't finished reading it, but does it explain Gallager decoding or RS decoding? At a first skim, it doesn't seem to, but that might be my lack of knowledge of the topic.
Thanks! It doesn't explain Gallager codes since I don't know much about them (but will look into them now!). It only briefly mentions RS decoding, since the RS erasure code uses Vandermonde matrices, and Cauchy matrices seem more foolproof for an intro article. I was planning on writing a follow-up article on PAR1 (which uses RS erasure codes, but slightly incorrectly) but alas, my free time isn't what it used to be...