Hello Klap-in,
"at the moment the development version search only in the namespaces it is placed in "
FYI: I tried it by putting the development {searchform} in the page of a sub namespace. Works great, but searches the whole (recent ponder stibbons) wiki.
Would be useful though to have it search only in one namepace. This is in the address bar:
http://localhost/wiki/doku.php?do=search&ns=factory%3Aconstruction&id=las