The Part-Time Parliament - Technical report by Leslie Lamport characterising a reliability issue in distributed networks in terms of a fictional parliament's consitution.
Algebraic Topology and Concurrency - Reports applying methods in algebraic topology to concurrent computation. Maintained by Stefan Sokolowski.
A Historical Note on `Geometry and Concurrency' - Online report by Eric Goubault, surveying the field from its prehistory in terms of classical interleaving and non-interleaving analyses of concurrency, through to modern applications of simplicial sets to fault tolerant computation.