I think it depends on whether you're asking about the Mac or Windows version. The Windows version requires the .NET framework, so it is almost certainly one of the .NET languages. One of the Atlassian staff members could be more specific.
I also think the Mac version is built with a more native language, but I don't run a Mac, or even know what options there are for Mac native languages.
Supported Platforms macOS Windows To make using Sourcetree as simple yet powerful as possible we embed (bundle) dependencies such as Git, Git LFS, and Mercurial. We strive to keep these...
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs