more like alpha or beta quality
The Freshmeat database lists this program as being production/stable, and the version number is 1.x, but to me this feels a lot more like an alpha or early beta release. There are just a lot of bugs and rough edges. The File>New command didn't work for me. The geographical information tab shows a world map, but the map doesn't actually seem to do anything (even when you set the latitude and longitude), and the sign conventions for longitude and time zone aren't specified. When you create a new card, the birthday defaults to the current date, and there's no way to delete the birthday without editing the text file by hand. There's no documentation on the web site, and although the Help menu has an item for a user's guide, that didn't seem to work, at least in the version I installed (the FreeBSD port). There's no Undo in the Edit menu, so you have a problem if you inadvertently click the large garbage can icon and delete a card. (Digging around in the .gnome directory, I did find that it seems to keep old versions of the file so you can roll back changes, but this doesn't seem to be documented or tied into the GUI in any way.)
If this had been listed as an alpha release, version 0.1, I would have said, "Wow, cool, looks promising!" But it's been a year and a half since the last release, so it looks like it's going to be permanently left in this rough form.
An open, cross-platform journaling program.
A scientific plotting package.