<p>+1 to all the answers provided. I think that all of them make good points and follow a general consensus that such questions appear "generally" on-topic.</p>

<p>I would like to add that from personal experience, I think that such questions are very educational. It is "trivial" for a learner to say for an LME model: "<em>Yeah, obviously: $y \sim N(X\beta +Z\gamma, \sigma^2 I)$</em>" or for ridge regression "<em>simple L.A. stuff: $\hat{\beta} = (X^TX+ \lambda I)^{-1}X^Ty$</em>". Nevertheless when going ahead and comparing solutions from different software implementation, small subtle differences not only become apparent, but also become appreciated for the impact they might have. Even something trivial like why  Python's <code>numpy.std</code> and R's <code>sd</code> do not give the same result highlight differences that can be educational and meaningful.</p>
