Currently many mature libraries and frameworks exist for each programming language and many advanced features were added to the languages. But what about the old projects where the language features were not advanced as now and no many mature libraries existed yet?

Let’s explore some old well implemented projects and discover how they are implemented.

https://www.codeproject.com/Articles/1195040/Lessons-to-learn-from-the-old-well-implemented-pro

That article is just an ad for a code metrics tool for C++. The Prince of Persia codebase is just barely looked at. "Oh, they used meaningful variable and function names, and the code is organized into several files." High quality analysis right there.

And I mean, Prince of Persia and Doom 3? It's like making an article about stone axes and Harrier jets.

@helios: What do you mean? It's very educational for what not to do for an article.