Red Steel was an expansion of the Mystara line in its waning 2e years (ca. 1995-96), focusing on the coastal areas southwest of Karameikos and the Known World. They called this area the Savage Coast, and it was introduced mostly by Bruce Heard's Voyage of the Princess Ark columns in Dragon Magazine a few years earlier.
The Red Steel/Savage Coast had a total of 8 products produced for it, under TSR's Odyssey line, though some were only released as PDFs after the line was discontinued. I seem to recall these beiong released for free at some point by one of the creators, but I can find no evidence now to back that up.
It had soem engaging ideas and a different sort of approach to adventuring, and it would have been interesting to see how it developed if given enough time/air. But alas.