How does AfterGRASP actually work (internally) compared to GLPRO or GRASP?
Both GLPRO and GRASP were text scripting languages run directly from their text source code. Although multiple scripts could be combined together with images, fonts and animations into a GL file, and then attached to a runtime, this was not compiling in the technical sense. The runtime would still load each script in original text source form as it was referenced, the script was checked for labels, and interpreted one command at a time.
AG is a multistage compiler that produces a tight stack based language based on FORTH with a LISP like syntax. This FORTH language is tokenized using a dictionary system for all strings including commands, functions, variables, labels, and text. This tokenized code, a stream of 32bit words, is what is actually loaded and executed by the runtime. You can find more details on the technical inner workings of AfterGRASP in the UPDATE.TXT linked to at the bottom of this page.
The focus has been on performance and producing a compact runtime, with a modular runtime for in-house use only. Current benchmarks of simple loops and expressions run around 50x the speed of GLPRO.
Although the AfterGRASP runtime runs on all 32 bit versions of windows from Win95 all the way to the latest Win2003, the AGEXE compiler does not work on the Win95,Win98,WinME series, only Win2000, WinXP and Win2003.