Limited image-based themes are available, but only XPM image files are supported. Gradient themes are also possible. The only way to classify it would be as basic, though don't expect a Windows style interface. FVWM is very stable, having been around for quite some time, but its future is questionable. Although it used to be the default window manager for various Linux distributions, it has been replaced in the last two years by Enlightenment,Window Maker, and various other newer win-dow managers.
New versions are probably under development but their releases are few and far between.
While designed with a small memory footprint in mind, its features make it less of a minimalist window manager than Blackbox. Various themes are provided right in the distribution but there is no obvious way to switch themes. It's a manual process, apparently. Applications can be added to the panel allowing you to launch them from their icons. The panel also provides a clock, load meter and mailbox icon.