UNU.RAN - Universal Non-Uniform RANdom number generators. UNU.RAN (Universal Non-Uniform RAndom Number generator) is a collection of algorithms for generating non-uniform pseudorandom variates as a library of C functions designed and implemented by the ARVAG (Automatic Random VAriate Generation) project group in Vienna, and released under the GNU Public License (GPL). It is especially designed for such situations where: a non-standard distribution or a truncated distribution is needed. experiments with different types of distributions are made. random variates for variance reduction techniques are used. fast generators of predictable quality are necessary.