The whiskermenu is great in itself, but unfortunately only accessible by mouse click or with Alt+F1. With a small program from Hans Chen a common behavior can be easily recreated:
ksuperkey redirects the signal triggered by the superkey in such a way that the whiskermenu opens. In principle, the Xfce can also be from house, but with ksuperkey the menu is opened as soon as you release the super key and no other key is pressed.

Installation
ksuperkey is available in some distributions (Arch, ROSA, OpenMandriva) directly from the package sources. For OpenSUSE and Debian exist OBS-Repositories. For Ubuntu up to version 16.04 there is a PPA, which should also work with Linux Mint. Also for Fedora there is an additional COPR-Repository.

However, compiling the program itself isn’t that hard, here is an example for Debian-based distributions:

  • Install dependencies:
    sudo apt-get install gcc make libx11-env libxtst-dev pkg-config
  • Some Debian-based systems may also need build-essentials, but you should have build-essentials installed anyway if you compile programs from time to time.
  • Get and build the code:
    git clone https://github.com/hanschen/ksuperkey.git
    cd ksuperkey
    make
  • Install system-wide for all users:
    sudo make install

Setup
With ksuperkey you can start the program from the program starter for testing purposes. It is important that Alt + F1 is set as the shortcut for the start menu. Just go to SettingsKeyboardKeyboard shortcuts for applications check and fix if necessary:

Now let ksuperkey start automatically with the following steps:
SettingsSession and Startup BehaviorAutomatically launched applicationsAdd → Enter ksuperkey and /usr/bin/ksuperkey.
After the next login ksuperkey starts automatically and the whiskermenu is accessible via the super key.