For a while I have been working on an open source mapping program as a free alternative to OCAD, today I released its first alpha version.
It is already possible to use it to draw most parts of an o-map. Because many comfort functions are missing and some bugs probably hide in it, I recommend to wait for some more versions if you want to use it for a mapping project. This version is intended for potentially interested developers and adventurous users, so I'd be happy about feedback to the published version, or if you are interested even about contributions to the project.
You can find more information and download links in the respective entry in the project blog:
http://oorienteering.sourceforge.net/?p=74Regards,
Thomas