idea/need: ntsyslog backend (for parsing Windows event logs archived via NTsyslog to a Unix machine).
But the actual reason for my comment was another suggestion. Have you considered implementing the same kind of backends inside a full fledged database? It seems to me at least PostgreSQL should offer enough extensibility to allow this. It could free you from dealing with the intricacies/limitations of an "SQL-like" parser and may open the door to more complex treatments (dunno if writing would be feasible).
Or maybe you would find this too overweight for your intended usage? (I routinely have to consider >30Go of compressed log files so, even a full-fledged database engine does not seem overkill sometimes.)
Gonna look at your tool anyway. Thanks for the contribution.