Crystal Space binaries for Debian/Ubuntu are provided here, in the "crystalspace" directory.
To run Skyscraper on Linux, first install the Crystal Space packages (the .deb files) and their dependencies.

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One easy way to get the dependencies is to install the packages (using "dpkg -i filename.deb"),
then run "apt-get install -f".

You can also add this site's Debian repository to your machine's config:
Add this line to your /etc/apt/sources file:
deb http://www.skyscrapersim.com/downloads/linux/debian unstable main

and then install the packages:
sudo apt-get update
sudo apt-get install crystalspace crystalspace-dev
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Then, extract the skyscraper tarball, and run Skyscraper (cd skyscraper; ./skyscraper).

Note - if no buildings show up in the file selection list when the program is
run, you'll have to navigate to Skyscraper's "buildings" subdirectory yourself.