[mtdewcmu]

"I'm in the early stages of a different project which will probably face a similar situation, except on this massive concurrency will be key..."

I'm a fan of native code, and I use C++ at work and C and C++ on my personal projects. In my last job I was doing web work, writing PHP for Drupal sites. My reaction to CppCMS is just to note that it wouldn't necessarily be easy to create a faster CMS using C++ versus PHP. Drupal sites can be slow as dogs, but the reason has nothing to do with PHP per se. The Drupal codebase is extremely bloated and fairly inefficient in its design, but even worse are the modules that get piled on, and there can easily be well over 100 modules on a site. I've watched the database queries that come out from a real site and it was stunning and appalling to see the volume and the redundancy that occurs on a single page. I was also amazed by the sheer quantity of PHP that gets loaded and parsed (if you're not caching) on a single page. So that tells me that PHP is pretty fast to be able to support that enormous edifice of code. It's not a guarantee that C++ would make you faster than an interpreted language, because the work that goes into generating a webpage plays to the strengths of interpreted languages and away from C++: you'd have to be careful and think through how to handle lots of strings and memory management. A good garbage collector is said to be faster than malloc/new when churning through lots of memory, because it can amortize the work and run on a background thread. I think lots of little strings could especially become a problem unless you planned out a strategy for handling them efficiently. Also, as others have pointed out, a lot of the issues with making a website fast aren't about executing code on the cpu. It wouldn't necessarily be easy to beat something like node.js at handling requests asynchronously, for instance. That stuff can be hard to write. So, I think it would be a good idea to do even a very high performance site in an interpreted web language first, then decide cautiously if there's a way to make it faster by replacing some or all of it with hand-written C++.