APLO: a simple modern APL
Alan Graham · 1989
APL0 is a simple modern APL written entirely in APL2. It is smaller than APL2 (or even VSAPL) but is more powerful. APL0 is implemented as a shell that translates APL0 statements into standard APL2. Details such as symbol table and workspace management are all handled by native APL2. The result is a powerful and malleable APL system.