  We present the universal two-loop splitting functions that describe the
limits of two-loop $n$-point amplitudes of massless particles when two of the
momenta are collinear. To derive the splitting amplitudes, we take the
collinear limits of explicit two-loop four-point helicity amplitudes computed
in the 't Hooft-Veltman scheme. The $g \to gg$ splitting amplitude has recently
been computed using the unitarity sewing method and we find complete agreement
with the results of Ref. \cite{Bern:2lsplit}. The two-loop $q \to qg$ and $g
\to q\bar q$ splitting functions are new results. We also provide an expression
for the two-loop soft splitting function.
