J for the APL programmer

Though J shares many concepts with APL, in many respects it is radically different, and almost all APL constructions that are in J differ in some way. These differences can be a stumbling block to the newcomer who thinks that J is simply an ASCII version of APL, prompting questions such as:• How do I save my workspace?• Why do J functions work along the columns and not the rows?• Can I have a version of J with □io←1?• Can I have a version of J with real APL characters?