Using code freely available under the GPL from the MQ sourceforge project, I've gutted out the hackish parts, and updated the code for a fps limiter.
You can download it Here.
To limit your fps type /maxfps fg/bg number .
FG limits it for the foreground window, bg the background window.
/fps toggles your fps indicator on and off.
/fps mode toggles the mode used by /maxfps from absolute to calculate.
To run, at the moment, you do need to load macroquest2.exe. For simplicity purposes, I've maintained the same loader, but this is not macroquest. The ONLY commands that function in this version are the ones described above.
As EQW/WinEQ2-type programs have previously been deemed to comply with the EULA, this one should be no different.