ChronosLNX is somewhat of a clone of ChronosXP for Linux systems primarily, although it will work on Windows and Macs, I think. It has most of the basic features of ChronosXP, but it might be missing some. If you have suggestions for lightening up or tidying up the code, visit the Issues page for it and bug me about it.
Copy the files to /usr/share/chronoslnx if you plan to use the *.desktop file included. If not, feel free to leave it where you downloaded it or place it somewhere else. You can also replace the icons for the planets and the program if you want to.
You can also clone the project with Git by running:
$ git clone git://github.com/ShadowKyogre/ChronosLNX