Lua is simple and elegant, and I much prefer it to Tcl.
Lua is in games and in LuaTeX, and when you have the choice of embedding a LISP, a FORTH or Lua in a larger application, it is often the most maintainable, runtime-efficient and low-memory footprint option of all.
I enjoy Lua and use it professionally, but when bash (and AWK) don't suffice, the glue is Perl. Because it has pipes which you can use to connect the output of one command to the input of another, or to a file.
Lua is simple and elegant, and I much prefer it to Tcl.
Lua is in games and in LuaTeX, and when you have the choice of embedding a LISP, a FORTH or Lua in a larger application, it is often the most maintainable, runtime-efficient and low-memory footprint option of all.