From a message I posted in one of the Ardour forums:
"Let's see what I have in ~/vst-linux:
Eqinox (EQ)
Soundcrab (SF2 synth)
HybridReverb2
KR-ReverbFS
Aspect (synth) and others from Loomer
Discovery (synth)
HyperCyclic (MIDI processor)
Manifold (audio signal processor)
dfx Transverb
Highlife (sampler)
ZR3VST (organ synth)
12 plugins from Michael Gruhn
38 plugins from mda
33 plugins from pizmidi
16 plugins from s-productions
There are more, especially from JOST creator Lucio Asnaghi... To be
honest and fair, not all these plugins work or work well (though most
do), and not all are particularly worthwhile (think LADSPA). However,
the pizmidi plugins are wonderful, Eqinox is great, Soundcrab is a
powerful alternative to QSynth, and so forth."
The post was a response to a statement that there are very few native VSTs.
Best,
dp