(Let's ignore all the friction I experienced with Neo4j's stuff that took up a couple of days and has resulted in my putting it to the side for now, not worth it at the moment for the pedagogical purpose of having a 2nd alien query language.)

Thanks to Alex Shinn and his sqlite3 Snow library, and his Chibi Scheme, getting the project up and running separate from a fork of Chibi Scheme took only a day, including creating a couple of cut down from it and customized Gnu Makefiles: https://github.com/Schemepersist/sdbi-chibi

Thanks to Takashi Kato for his PostgreSQL wire (net) protocol Snow package, that required no changes at all, except for renaming the locations (e.g. (sdbi connector net postgresql), or (sdbi connector ffi sqlite3)). I was already up on the learning curve to set up PostgreSQL, create a database, etc., so it and Sqlite3 have complete tests to create a table, insert a row, retrieve it, and drop the table.

Thanks to Apache Cassandra, and DataStax, Inc. for making it absolutely frictionless to install both the database and the latter's C API, which includes a bunch of placed in the public domain example programs, a total class act. And again thanks to Alex Shinn for his marvelous Chibi Scheme FFI, and examples of how to hack around it not handling const arguments or returns in the sqlite3 Snow library. Not long ago I got finished executing the statement "SELECT release_version FROM system.local" from the simple.c example, and got the valid string value for the single row and named column return.