Realsoft 3D JavaScriptPlugin library (filename r3js) links against SpiderMonkey JavaScript engine.

The JavaScriptPlugin is a property of Realsoft Graphics Oy. SpiderMonkey is Mozilla's JavaScript engine written in C/C++. It is used in various Mozilla products, including Firefox, and is available under the Mozilla Public Lisense 2.0 (MPL2) https://www.mozilla.org/en-US/MPL/2.0/

JavaScriptPlugin is also available in Source Code Form, as described in Section 3.1 of MPL2.0 license. The source code is included with Realsoft 3D binary distribution package, located in scripts/js folder. You can also obtain the copy of the source code from Realsoft Graphics Oy <info@realsoft.com>.