The dbtw_d_main.js, dbtw_r_main.js and dbtw_t_main.js for CGI all use the ISAPI DLL... this kinda defeats the purpose...

They don't actually use the DLL in practice, despite the fact that the .JS file lists the DLL. The code passes along whether it's supposed to use the EXE or the DLL and uses the right one for Next Record buttons, "see also" links, expand record jumps, etc.