Where is a filter to convert FrameMaker files on Linux?

Adobe FrameMaker is a “powerful authoring and publishing solution for technical communicators”. I used FrameMaker a lot from the mid 90’s until 4/5 ears ago and I have to say that I found it to be a great program, with a better, more productive interface than either Ms Office or OpenOffice. However, FrameMaker is a proprietary, really expensive product that doesn’t even run on Linux, so no matter how good it is it’s almost sure I won’t use it anymore.

The problem is that I still have on my computer several personal documents that I wrote and saved in FrameMaker format (.fmk file extension) in the 90’s, that is before I realized how badly proprietary file formats can impact economy, culture and personal stuff. Therefore, right now those files are just wasting space on my hard drive, even if I’d really like to access again some of them. I am sure there are many thousands of people in the same situation.