Command used in TclOO and XOTcl to call the next method in a method call chain. Syntax is different between two extensions (mainly because TclOO requires Tcl 8.5) and semantics is slightly different (TclOO's next effectively does an uplevel inside itself).
In TclOO/Tcl 8.6:
The nextto command takes an additional class argument that specifies which implementation on the call chain to go to.