I attended a presentation at OpenSourcery by Chris Anderson about CouchDB. He showed off Futon, which is CouchDB's online web interface, which allows one to do normal CRUD, as well as set up replications, run tests and set configuration variables. It has some simple JavaScript functions which are basically map/reduce elements and it seems to be tightly integrated with jQuery. When I asked about Prototype I got the "Why are you still using Prototype?" spiel. Perhaps I should actually look into why people think jQuery is so much better. Anyway, Here are my rough notes of the interesting features of CouchDB that caught my eye:
HTTP server + JSON Doc DB (key/value pairs), RESTful
Incremental Map reduce views
peer-based replication
multi-master OR push all changes to one write-master and + read slaves
concurrency over serial speed
Ex: lotsofwords.com = 120GB database, 200ms response
written in Erlang
sharding via hash functions
documents vs. relations
each doc has a "revision"
first in wins
standalone apps via _external servers
p2p replication - this is really cool and powerful
_external servers - api to parse request as json, filter it and then return
rollup = reduce
re-reduce phase =~ aggregate
