Hi Agil,
Here's a tutorial for HMG written by Giovanni (HMG Forum Member):
http://www.elektrosoft.it/tutorials/hmg/hmg.asp
And the best way to learn HMG is to write your code from it. HMG (Official at HMG Forum) and HMG Extended (
http://www.hmgextended.com" onclick="window.open(this.href);return false;), which is fork out of HMG Official and both use Harbour Compiler. Both distribution contains samples from basic to advance. You can use those samples as basis to get started. You may also consider downloading the Harbour nightly build and browse the codes. The link is:
http://harbour.github.io/ The manuals at elektrosoft.
There are also other variants as well apart from HMG Official and HMG Extended like HwGUI (from which HMG Official has been forked out), ooHG and HBQt.
Basically there's 20% to 30% difference between Clipper code and HMG code. Those are the codes associated with events and control objects actions. The rest remains Clipper code except the control flow (logic).
I basically used the PRG format of form layout and sometimes used the FMG forms. I tucked them inside a zip file and expand to a temporary folder when the program starts and erased them when the program terminates. Well, I did that to hide it from curious end users who in one way or the other finds it amusing to mess with the program and always come-up with the famous innocent phrase, "I don't know, a while ago its working fine".
Good luck,
Danny