SaveDefinitions is an option to Manipulate and related functions that specifies whether current definitions relevant for the evaluation of the expression being manipulated ...
Selectable is an option for displayed objects, cells, and notebooks that specifies whether their contents can be selected interactively using the front end.
Skeleton[n] represents a sequence of n omitted elements in an expression printed with Short or Shallow. The standard print form for Skeleton is <<n>>.
StringTrim["string"] trims whitespace from the beginning and end of " string".StringTrim["string", patt] trims substrings matching patt from the beginning and end.
SyntaxQ
(Built-in Mathematica Symbol) SyntaxQ["string"] returns True if the string corresponds to syntactically correct input for a single Mathematica expression, and returns False otherwise.
SystemOpen["target"] opens the specified file, URL, or other target with the associated program on your computer system.
Underscript[x, y] is an object that formats as UnderscriptBox[x, y].
$CompilationTarget gives the default value for the option CompilationTarget of Compile.
To run Mathematica using a network license, both the client machine and the license server must be on the network, and MathLM must be running. If you do not have a MathLM ...
$CUDALinkPath is the path to the CUDALink application.