I guess I now have a sort of beta release of Multiverb. I have put some source files on GitHub under user name professorwub. The repository includes the following:
Multiverb class files: Multiverb.h Multiverb.cpp DelayLine.h DelayLine.cpp
Additional files for LV2 version: manifest.ttl Mverb.ttl Mverb.cpp makefile
You need lv2-c++-tools to build the LV2 version. I have built a VST version for Windows using JUCE, but my code might fit other environments as well.
Note that although the LV2 version defines two audio inputs and two audio outputs, it seems to work on mono tracks in Audacity. The VST version checks the number of tracks before processing each block of data. I am not sure how the LV2 version can determine the number of tracks and I refuse to ask the user to provide this info.
Comments more than welcome!