I love Iron Heroes. Yup, I know. Shame on me. 2nd edition is my game of choice, but there's some definite appeal to the game. It's a low magic and scarce magic campaign. It has no non-human races available for play. That last part makes it especially good as it completely prevents the presence of what I call "Humans-in-funny-suits-syndrome" that seems to take place in many games(the worst offenders include all metallic dragons in the MM as written, The Council of Wyrms setting, and pretty much every MMORPG ever made) where all the non-humans are only differentiated from humans by stats and appearance. About the only game this was ever acceptable in(to me) was Shadowrun, because it really was a physical appearance issue more than personality.
Anyway, Iron Heroes. Recently a free PDF of a setting for the game. At first I thought it was the long awaited, but thankfully will never come, Swordlands setting(things always seem to sound great until people start getting into specifics, at which point it almost always horribly ruins it). Instead it's a setting called Bloodwood(you can get the setting PDF for free over here) or Lakeshore depending on your point of view.
Oddly enough, the setting is almost completely system neutral(2 monsters from the Iron Heroes Bestiary are mentioned, and the Spiritualist class from the IH Player's companion is mentioned twice, and all of this can easily be altered or ignored altogether).
Long story short(too late) I salivated. I drooled. I immediately sat down and started trying to figure out how to put this sandbox together using 2nd edition AD&D. A few hours later I was banging my head against a wall. As written, there's only 2 non-magic using classes in the Core 2nd edition rules(Fighters and Thieves, and thieves get to use spell scrolls). And only a scattered handful altogether. After a short burnout period, I began to start working on it again.
As much as I'd absolutely love to keep the nothing but humans rule of Iron Heroes, I know my players would lynch me. Because of this I added a handful of Halfbreeds. I took the Half Ogres and Half Orcs from the Complete book of humanoids, and wrote it so the players knew that these characters are those raised "human-side."
The last race I'm allowing is a mix of two different rules sets. The first being the Tiefling from Planescape, and the second being the Progeny rules from the Glantri: Kingdom of Magic Mystara boxed set. I then named the resulting spawn, "Changelings" and I'll go ahead and put the changelings in their own little post.