The interpreter is. But if you write vectorised code, we frequently are able to outperform Matlab.<p>Matlab used to have the same problem, and they even used to have docs on how to vectorise. When I first learned Matlab in 2004, they told me, &quot;don&#x27;t use loops&quot;. Twelve years later, you&#x27;re supposed to write all the deeply-nested loops you want.<p>So yes, most Matlab code out there is loopy, so it&#x27;s slow in Octave. But if you write it for Octave and don&#x27;t make it loopy, it&#x27;s quite good.