Various ideas have been proposed and systems introduced in an attempt to improve Tcl perfomance via some kind of script compilation. This pages exists to enumerate and organize those ideas.
Since version 8.4, Tcl has featured the ability to automatically translate scripts into bytecode where feasible, and, for the most part, script authors don't have to do anything particularly special to take advantage of it. Lambdas and procedures are automatically translated to bytecode, and where feasible, so are arguments to expr-like commands such as if, while, and expr itself.