The easiest way to connect to Files Pro from any operating system is to connect to the Web Interface with a web browser.
It is also possible to connect to Files Pro from any client software which supports the WebDAV protocol. For example you can use AnyClient (www.anyclient.com), which is a free Java WebDAV client.
On Linux you can use Davfs (http://dav.sourceforge.net/). If you have a recent version of the Gnome or KDE desktop you should already have WebDAV support built-in.
To connect form KDE enter Files Pro URL into Konqueror's Address Bar. You should replace http: with webdav: e.g.
webdav://192.168.0.2