VK9 is described as '(Formerly SchaeferGL). Runs Direct3D 9 applications on Windows or Linux (/w Wine) over Vulkan'. There are five alternatives to VK9 for a variety of platforms, including Linux, Mac, Windows, Wine and FreeBSD. The best alternative is PlayOnLinux - PlayOnMac, which is both free and Open Source. Other great apps like VK9 are DXVK (Free, Open Source), D9VK (Free, Open Source), Direct3D 9-to-11 (Free, Open Source) and DXUP (Free, Open Source).
PlayOnLinux is a graphical frontend for the Wine software compatibility layer which allows Linux and Mac users to install Windows-based video games, Microsoft Office (2000 to 2010), Microsoft Internet Explorer, as well as many other applications.