We want to avoid sticking to particular compilers/interpreters. An expert in MSVC should not be penalized only because we use GCC. Also we design the tasks so that they are compiler-agnostic (actually they are even language-agnostic). It is sometimes a bit tricky due to non-standardized type sizes (e.g. C, C++, PHP), but generally the tasks can be solved using very limited and portable subset of a language.