Wasp's WPL printers use WPL as their native programming language, and offer emulation of ZPL, EPL, and DPL. Here are some programming manuals:

WPL (Wasp Printing Language):
https://dl.waspbarcode.com/kb/printer/WPL_WPL2_Programming.pdf

ZPL (Zebra Printing Language), including ZPL-II:
https://dl.waspbarcode.com/kb/printer/zplii-programming-guide-rev-a.pdf

EPL (Eltron Programming Language):
https://dl.waspbarcode.com/kb/printer/epl2-programmer-manual.pdf