UseFrontEnd[expr] evaluates expr in an environment where the kernel can make use of the services of the notebook front end.

TetGenDetectIntersectingFacets[points, facets] returns a list of points and intersecting facets.

CCompilers[ ] returns the list of C compilers supported for this version of Mathematica that can be found on your system.CCompilers[Full] returns the list of all C compilers ...

CloseGUIObject[interface] closes a live GUIObject instance.CloseGUIObject[] requests that an interface close, when called within a Script block.

Introduction Developing GUIs Advanced Topics

$BenchmarkSystems gives the names of systems for which the MathematicaMark8 benchmark data is known.

EasterSundayGreekOrthodox[year] gives the date of Easter Sunday according to the Greek Orthodox Church using the Gregorian system.

EasterSunday[year] gives the date of Easter Sunday in the Gregorian calendar system.

ApproximateVertexCover[g] produces a vertex cover of graph g whose size is guaranteed to be within twice the optimal size.

Automorphisms[g] gives the automorphism group of the graph g.