I'd say "well .NET is cross platform" but knowing the average company on .NET it's probably version 3.5 and running off a windows 95 server that hisses whenever someone gets too close to it.
You can read and build the source code yourself if you're really worried what some Russian FOSS contributors are up to, but I can assure you it's going to be a lot less sus that whatever a proprietary application can do without any ability to audit and check the code.