Does ArcaOS really run OS/2 applications, like Mesa/2 and dbExpert and other well-known titles?

Yes.

ArcaOS runs OS/2 applications natively because it is OS/2. Your favorite, classic OS/2 applications, such as Lotus Smartsuite, Mesa/2, dbExpert, Relish, Describe, and so forth install and should run under ArcaOS just as they installed and ran under classic OS/2 Warp 4 – only better.

ArcaOS provides better memory management and hardware support for newer systems than OS/2 Warp 4. This means that applications which may have been somewhat “resource constrained” on older systems are now “set free” under ArcaOS to realize their full performance potential.

Be productive again. Put that great software in which you invested years ago back to good use.