An application running on Win32s has the shared address space and cooperative multitasking characteristics of Windows 3.1.
However, allowing user-level thunking greatly complicates attempts to provide stable memory management or memory protection on a system-wide basis, as well as core or kernel security—this allows poorly written applications to undermine system stability on Win32s, as well as the Chicago-kernel systems.
Win32s-compatible applications could be built using Microsoft's development tools, as well as at least Borland C++ 4.x and Symantec C++ (now Digital Mars C++).
However, several program compilation options (such as EXE relocation information) and DLLs which were implicit in Windows NT 3.1 have to be included with the application in Win32s.
Warcraft II: Tides of Darkness, a DOS game, included a level editor that required Win32s to run.