If your Linux system use deb packages,see Installation on Ubuntu.

For other Linux system you can download rpm or tar packages from the Sourceforge download link.

The requirement are Gtk2 and libpasastro.

See also the list of dependencies to install to take full advantage of the software.

You can also compile the source code using Lazarus.

To open DSLR raw files you need a version of libpasastro build with LibRaw support.
Unfortunately the LibRaw programming interface is not stable across LibRaw version, so libpasastro must be build specifically for your system or it not work.

On Fedora you can use libpasastro packaged with the system.

For Ubuntu you can simply install libpasastro from this PPA:
https://launchpad.net/~pch/+archive/ubuntu/ppa-skychart

For other system you need to compile and install libpasastro from source after installing the libraw-dev package.
As a last resort you can install the dcraw package, but this is less performant as it need to work with temporary files.