1. A system comprising: at least one processor; at least one memory coupled to the at least one processor and storing instructions configured for execution on the at least one processor, the instructions comprising: a user interface for testing options; a markup language application including a first set of instructions expressed with one scripting language and a second set of instructions expressed with a markup language; a selected scripting language engine configured to interpret the one scripting language, wherein the selected scripting language engine is selected for a debugging session from among a plurality of scripting language engines using the user interface of testing options, wherein each scripting language engine of the plurality of scripting language engines is configured to interpret the one scripting language; a communication module configured to receive at least packed command data associated with the debugging session; an unpack module configured to: generate unpacked command data based on the received packed command data; and provide the unpacked command data to an embedded test tool; and the embedded test tool configured to: interact with the selected scripting language engine; and generate debugging output responsive to the unpacked command data, the debugging output generated through execution of the markup language application.