Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
I'm no expert on this either, but OpenStudio Application is developed in Qt C++.
A single thread is generally used to render the application, which isn't something specific to OpenStudio, but rather because rendering actions aren't really parallelizable.
That being said, a few limited actions are spun into separate threads, especially when you launch the application: it starts the measure manager, and it uses the VersionTranslator to update your OSM model, and the OSM libraries you have set (defaults to office.osm and hvac_library.osm) to match the OS Application version[1]
[1] see source code in OpenStudioApp.cpp#L193:L199
