30 day fully featured free trial available here https://tonelib.net/gfx-overview.html. Source: almost 2 years ago

I use tonelib gfx for amp and cab sims(I think it has a free trail). Source: almost 2 years ago

This is on discount right now and it has a little bit of everything: https://tonelib.net/gfx-overview.html. Source: almost 2 years ago

It's not short, but I was introduced to the concept in a video series on FLOSS Linux audio tools: https://www.youtube.com/watch?v=hdPPPeq82hw&list=PLf_MTToSAxRITjUHgpIPUQTZdGvNQR-0p&index=1 Specifically, you can play with it yourself with a tool like ZynAddSubFX's (https://zynaddsubfx.sourceforge.io/) virtual keyboard, where you can enable microtonal under scale settings and tweak to whatever tuning you want (see... - Source: Hacker News / 7 days ago

I've also used ZynAddSubFX, which is also a very powerful synth, though its interface (at least to me) is a bit of a clusterfuck. You could also try browsing this index of microtonally capable synths on the xenharmonic wiki. Source: about 1 year ago

The code for this can be found here on shadertoy! The audio was made with an Ibanez bass, Guitarix, Hydrogen Drums, ZynaddSubFX and Ardour! Source: over 2 years ago

Here is an additive synth - https://zynaddsubfx.sourceforge.io/. Source: over 2 years ago

There are VSTs for Linux. Surge, Vital, and ZynAddSubFx are three prominent examples, as well as OxeFM, Dexed, and plenty I'm forgetting. Surge and Zyn also come LV2 and DSSI, which are native Linux formats. For those who don't know, the VST3 SDK supports Linux, and is released under GPLv3 by Steinberg. Source: almost 3 years ago