MaximuS_GПо ссылке, которую привел Паганель , такое написано:
However, when the loads become more then average, the process of scale-up using existing web frameworks may be painful:

Low performance of dynamic or JIT languages enforces you to add more servers even on quite small loads.
The caching becomes more complicated and less efficient because the system becomes distributed and does not scale-up linearly.
Creation of such system requires skilled stuff and costs even more.
CppCMS allows you to increase the performance of typical system by an order of magnitude and thus:

Remove requirement of maintaining a big server farm where few servers or even single one would solve the load problems.
Reduce maintenance costs and power consumption.
То есть получается по быстродействию платформа написанная на C++ будет быстрее, чем написанная на PHP/Python?
В общем, да (зависит от того, как код писать). Кстати, питон - самая медленная в мире штука. :)