With the appearance of these two sales: https://www.humblebundle.com/sierra-bundle-strikes-again http://store.steampowered.com/bundle/2249
I wonder whether the Midkemia related games (Betrayal At Krondor, Betrayal In Antara, Return to Krondor) work without the Steam client.
Especially Antara, because I think the best way to get around compatibility issues with current Windows versions (I'm running W10 64bit) is to install a past version of Windows (95, 98) in a VM. But Steam only supports Windows XP or newer, and who knows how long until Valve drops support for XP and Vista (which are in the official system requirements for the Steam version of Antara).
Another possibility might be Wine support for these games from the 90s. But not sure if Wine can support a W95/98 game and Steam (which requires XP at least) at the same time.