Trigger based logging alternative to table_log

I have some code which uses table_log (
http://pgfoundry.org/projects/tablelog/) to keep a log of changes to
selected tables. I don't use the restore part, just the logging part.

It creates a new table for each table being logged, with several additional
columns, and adds triggers to insert rows in the new table for changes in
the original.

The problem is that table_log hasn't been maintained in nearly 10 years,
and pgfoundry itself seems to have one foot in the grave and one on a
banana peel.

There are several other systems out there which store the data in hstore or
json, which I would probably use if doing this from scratch. But I'd
rather preserve the existing log tables than either throw away that data,
or port it over to a new format.

Is there any better-maintained code out there which would be compatible
with the existing schema used by table_log?

Cheers,

Jeff