Hi Steve! Personally, I'm using SDI application because of solid look and feel (like any VC++ app). But I must admit that I have more headache with SDI than with old buddy MDI app... The one of big issues is a managing menus on top-level form. I swear to God, it is the biggest trap from M$, I spent over a week to bring it to work... It won't work how it docummented in Help or any other sources. Said all of above, I would like to say: But I like it <g> >I usually use SDI, but for personal reasons, nothing overly scientific. >What are the issues for creating one type of app versus the other?