[ANN] a graph database: sph-dg

[tantalum]

hi. in the past year i have implemented my idea of how a basic graph
database should look like, with guile. and today it seems quite stable
and usable.

it uses a memory-mapped data store to persist bi-directionally ordered
(or weighted) pairs (what would be edges of a graph), bytevectors,
strings and signed integers as well as references to files in the
filesystem.
it currently supports at most one open database per process and a socket
based interface for inter-database communication. it is supposed to be
concurrency safe and there are extended and experimental features
available in a separate sph-lib-dg library (http://sph.io/content/3217).
for example a semantic userspace filesystem, special query processors or
procedures for the creation of data structures like sets and lists using
pairs/edges

here is the link to the project page: http://sph.io/content/2faf