Yes, there is software named "tilp". However the package in the ubuntu repo is a bit outdated, so you must install it from source. But that isn't so hard, here is how to do it:

First download this script: http://lpg.ticalc.org/prj_tilp/download/install_tilp.sh
Copy it to your home directory ("/home/northern_snow")
Open a terminal (Applications --> Accessories -->Terminal)
Run this:
sudo apt-get install subversion autoconf automake libtool libglib2.0-dev zlib1g-dev libusb-dev libgtk2.0-dev libglade2-dev libsdl1.2-dev gettext bison flex groff texinfo xdg-utils libarchive2-dev intltoolThis will install all the dependencies to compile tilp.
Then run this:
chmod +x ./install_tilp.sh
sudo ./install_tilp.sh
You will be asked for your password, type it (it's normal that you don't see it while typing).
Then wait for the installation to finish.

When it's done (without any errors) you have successfully installed and compiled tilp. To use tilp just run "sudo tilp" in a terminal.

Edit: updated for the latest version of TiLP

RMB is Chinese yuan ...
and 1750 Chinese yuan = 190.474639 Euros.

Looks to me like its more expensive with you.

ouch, thats bad internet!
Good luck anyway!

Thanks Jim for the more detailed procedure, I've bookmarked the link and I'll be pointing people at this topic

The version in SVN now has good support for the Nspire CX series.