Redis is an awesome, high-performance memory resident data store.
Mostly what we use it for is in a Pub/Sub
Installing Redis
emerge -av redis
apt-get install --yes redis-server
Configuring Redis
The configuration is generally stored in /etc/redis.conf.
bind 127.0.0.1 port 6379 timeout 16 tcp-keepalive 60 loglevel notice logfile /dev/null syslog-enabled yes syslog-facility local1 syslog-ident redis # 32MiB maxmemory 33554432