The pilot-link set of utilities are the most common means of connecting a Linux machine to a Palm. These programs allow installation, querying, deletion, and manipulation of all the data stored on a handheld. They are command-line utilties, but many graphical Palm tools (e.g. Jpilot) use them as their back end.
The suite also includes libraries that allow programs written in C, Java, Perl, and Python to communicate with Palms.