There are two stackexchange sites that seem to have a bit of overlap: CS and CSTheory. CS states that it is for: "programming language semantics, formal methods ... or any other topic in theoretical or applied computer science at any level." where CSTheory is for "Specific research-level questions in theoretical computer science"
Does this mean that the difference is that CS is more geared towards questions that have a known answer, whereas CSTheory is for research only questions? For example, "What is the fastest known unification algorithm?" would go on CS while "Can unification algorithm X be made more efficient by Y?" would go on CSTheory?
Or do the two domains simply overlap?