Lately I've been working on the gnuais source code, improving it so that it could be used to decode AIS and feed aprs.fi using Linux. My changes are in the SVN trunk (not in any released version yet). It's generally working, I just haven't done the actual "feed aprs.fi" part yet. But it's getting closer. The decoder isn't as good as in aismon/shipplotter - if you have DSP coding experience, your help is welcome on this project!
I've also modified some Televa 703-LYVV VHF FM receivers from the cold war era to be used as AIS receivers. "Brand new" (but a bit over 30 years old - like myself) commercial NBFM receivers in their original factory boxes, built to be installed at bomb shelters and such, but (luckily) never needed. Going to install a couple of them here in Helsinki, with directional antennas pointing southeast and southwest on the Gulf of Finland. We installed the antennas and cables during the last couple weeks, they're just waiting for the gnuais feeding code.