All of the Geodatabase formats from ESRI are proprietary, and not open, so we have to be a little careful how much of a commitment we make to supporting them. There are two major kinds, and we'll go over the differences between the two.
The newer "File Geodatabases" (which are actually folders that end with .gdb and contain lots of files on other platforms, but on the Mac look like a single file) are supported starting with Cartographica 1.4 for vector data. Thanks to the availability of libraries from ESRI which allow us to read and write this format, we can import and export File Geodatabase format vector files. Unfortunately, the Raster format is not currently supported by ESRIs libraries, and therefore not supported by Cartographica.
We've also been informed that File Geodatabase support from the ESRI libraries requires that .gdb data be from at least ArcGIS 10 and it will not read 9.3-format .gdb data. We have information on upgrading databases, but it will require somebody with ArcGIS 10 to make it happen.
The older "Personal Geodatabases" (files that end in .mdb and contain just feature data, and no rasters) are generally supported. This is to say, we support reading them and have had good luck with the files that we have tested. However, since the format is proprietary and unsupported by ESRI for use outside of ArcGIS, we can't guarantee that all files will be compatible.