optional_depends libusb --enable-usb --disable-usb \
  "1-Wire usb DS2490 support" &&
optional_depends avahi --enable-avahi --disable-avahi \
  "for zero-config autodiscovery" &&
optional_depends fuse --enable-owfs --disable-owfs \
  "for filesystem-style access via FUSE" &&
# There are various bindings to scripting languages. I am not testing
# all of them.
optional_depends perl --enable-owperl --disable-owperl \
  "for Perl bindings" &&
# TODO: mess around with python versions, --with-python and such
optional_depends python --enable-owpython --disable-owpython \
  "for Python bindings" &&
optional_depends php --enable-owphp --disable-owphp \
  "for PHP bindings"
optional_depends tcl --enable-owtcl --disable-owtcl \
  "for Tcl bindings"
