Thanks for the shout-out. Two random comments:
1) Maltego - it's actually now been adopted by one of our senior reporters, and they're very very thrilled about it. Especially Paterva CaseFile, which is less focussed on the data enrichment aspect than the actual Maltego package.
2) Somehow, I found this OSINT package here quite inspiring: https://bitbucket.org/LaNMaSteR53/recon-ng - it's basically a whole bunch of sleuthing modules in social media that all write to a common core set of tables. While the code base itself is pretty horrific, I like the simplicity of the setup.
So I've been using a similar approach for two of our recent investigations and extracted the approach into a very prototypical package: https://github.com/occrp/corpint . This basically reads a seed of entities from a CSV file and then goes out to Orbis, OpenCorporates, Aleph and Wikidata to find additional details. Finally, there's a merging layer which prompts the user to confirm valid matches.
The resulting graph is loaded into Neo4J and explored using Linkurious. While it's too early to speak of massive investigative break-throughs, I like how quickly it let's me turn a list of 10 companies into a 1000 node graph