TCL is a better Scheme

This is a tail-recursive naive implementation of factorial for TCL 8.6:
proc fac-tr {n {k 1}} {
if {$n <= 1} {
return $k
} else {
tailcall fac-tr [- $n 1] [* $n $k]
}
}

>>4

Show me another language with S-exps AND tons of maintained libraries.

You seem to be under an impression that "tons of maintained libraries" is a property of being a LISP and a good thing overall. This is wrong. Powerful metaprogramming allows real LISP programmers to grow their own dialect of the language that fits perfectly to the problem at hand instead of mucking with one size fits all shit libriaries.