  A \emph{loop} $(B,\cdot)$ is a set $B$ together with a binary operation
$\cdot$ such that (i) for each $a\in B$, the left and right translation
mappings $L_{a}:B\to B: x \mapsto a\cdot x$ and $R_{a}:B\to B: x \mapsto x\cdot
a$ are bijections, and (ii) there exists a two-sided identity element $1\in B$.
Thus loops can be thought of as "nonassociative groups". In this paper we study
standard, internal and external semidirect products of loops with groups. These
are generalizations of the familiar semidirect product of groups.
