We run SppDb happily on our iMac using CrossOver Version 18.0. The figure below shows the database running on a Mac with the High Sierra operating system. We have reduced the size of the SppDb window to enable the Mac desktop to show clearly and to show that other applications can be used while SppDb is running.
PlayOnMac
As an alternative, you might try installing PlayOnMac software. It is free of charge, and SppDb appears to run correctly, as shown below.
The large-screen Mac lets us run our CAD software (gCADPlus) and SppDb together. The figure below shows SppDb on the left and gCADPlus on the right, both running under CrossOver.
Using SppDb, we can search for a particular species to meet a need in developing CAD designs and save much time because the path to the image file can be copied directly into the insert raster tool in gCADPlus.
If you would like to try this combination on your Mac, download SppDb (it’s free from this site’s download page) and a trial copy of Crossover. Install CrossOver first, then SppDb.
We have also run SppDb successfully under Ubuntu and Parallels.