I've got a project that I currently build native libraries for Android, iOS, Linux and Windows Standalone - I am very keen to get a WebGL build working. My native library works well on all the mentioned platforms - does this provide any indication if it will also work for WebGL? I currently use posix sockets, pthreads, etc - for the Windows Standalone dll I'm using mingw32/64 on linux, for Android I use the ndk on Linux, for iOS I use clang++ From the brief bits I've seen online it appears that I can drop my source code somewhere and Unity will build it as part of the build process. Questions: Where do I put the source to achieve this? How would I reference the native code from c#? (does it use the same [DllImport ("__Internal")] notation as an iOS AOT build?) What about compiler flags, include folder, etc. Are there any restrictions on what C++ code can be included? Are all the standard libraries available? For example: STL? What C++ compiler is used by Unity for this process? Any pointers do some documentation, how-to's, resources of any kind? Any assistance will be greatly appreciated.