While you can technically still download it from the Visual Studio Subscriptions archive, you will run into walls:
Visual Studio 2015 Community Edition is a free, full-featured integrated development environment (IDE) from Microsoft that allows developers to create high-quality applications for a wide range of platforms, including Windows, Android, iOS, and web. This version of Visual Studio is ideal for individual developers, hobbyists, and small teams who want to take advantage of the same tools and features used by professional developers. visual studio 2015 community edition
Looking back, 2015 was a transitional year for Microsoft. They were embracing open source, shipping .NET Core (preview 1), and finally fixing their C++ story. While you can technically still download it from