I’ve been using OpusModus for years. It’s a slightly different animal from a lot of other apps (like Overtone) in that it has a steady crowd of experienced composers who are taking composition principles and abstracting them up to the level of classes. That’s not to say that Overtone doesn’t support many of the same compositional techniques (Such as a Reich phase). Overtone can get you there, but the OpusModus community seems to support these artistic-movement-based ideas in a more formalized way. Again, this software is supported by a community of classical composers, so if a sine wave is mentioned, it’s more likely as a generator for pitch content than synthesis.
The output of OpusModus is focused as a default on orchestral instrumentation. Now, to a lot of developers, the response to that will be “I can modify that any way I want with some basic Lisp and, hey, it outputs MIDI to any DAW, etc.” You would be correct, and in addition the developer of OpusModus is working on audio synthesis components. However, as of today it may not have quite the involvement with sampling and synthesis that some electronic musicians might prefer.
For this reason I think that the thing which makes OpusModus stand out as a software and a community is that it is by and for composers who are focused on depth in music theory and the integration of concert music with electronics rather than someone who is more focused in the synthesis world exclusively.
I use OpusModus with notational output for orchestral instruments as well as MIDI data which I use to trigger electronic processes. Additionally, it provides a basis for graphical notation which adds another view as I’m defining my composition as well as output for print copies in concert guides.
That said, I still prefer to add in my own elements once the score is output. In addition to the structure, the gestural elements and extended techniques are critical to the idea in the music for me. For some reason I don’t like the idea of having software generating those. It’s a really neurological/human aspect of the music I want to keep. Not sure why, it’s just my thing.
Another example - are a lot of applications which provide tools for stochastic composition (OpusModus is one) but that doesn’t mean you can immediately create music as powerful as Xenakis’ Metastasis. I’ve found that OM works well for connecting the parametric theory and the synthesis/sampling aspect of music with the non-algorithmic world of working with other musicians in the studio and live performances.
Hope this all makes sense.