Moo is a light-weight object oriented programming framework which aims to be compatible with Moose. It does this by detecting when Moose has been loaded, and automatically "inflating" its classes and roles to full Moose classes and roles. This way, Moo classes can consume Moose roles, Moose classes can extend Moo classes, and so forth.

However, the surface syntax of Moo differs somewhat from Moose. For example the 'isa' option when defining attributes in Moose must be either a string or a blessed Moose::Meta::TypeConstraint object; but in Moo must be a coderef. These differences in surface syntax make porting code from Moose to Moo potentially tricky. MooX::late provides some assistance by enabling a slightly more Moosey surface syntax.