Results are appearing a bit sooner at https://docs.google.com/spreadsheets/d/1mI2o0smlVC_TyzhsnweL... and https://twitter.com/britainelects

Definitely the implementation of a (simplified) Scheme interpreter in Scheme we were doing years ago in a functional programming course on university. It made me fall in love with functional programming.

What about TinkerGraph: http://tinkerpop.apache.org/docs/3.1.0-incubating/#tinkergra...

It is "TinkerGraph is a single machine, in-memory (with optional persistence), non-transactional graph engine that provides both OLTP and OLAP functionality."