2.2.1 (unreleased)

Internal API: Client#call and family are now called with a single array argument, since splatting a large number of arguments (100K+) results in a stack overflow on 1.9.2.
The INFO command can optionally take a subcommand. When the subcommand is COMMANDSTATS, the client will properly format the returned statistics per command. Subcommands for INFO are available since Redis v2.3.0 (unstable).
Change IO#syswrite back to the buffered IO#write since some Rubies do short writes for large (1MB+) buffers and some don't (see issue #108).

2.2.0

Added method Redis#without_reconnect that ensures the client will not try to reconnect when running the code inside the specified block.
Thread-safe by default. Thread safety can be explicitly disabled by passing :thread_safe => false as argument.
Commands called inside a MULTI/EXEC no longer raise error replies, since a successful EXEC means the commands inside the block were executed.
MULTI/EXEC blocks are pipelined.
Don't disconnect on error replies.
Use IO#syswrite instead of IO#write because write buffering is not necessary.
Connect to a unix socket by passing the :path option as argument.
The timeout value is coerced into a float, allowing sub-second timeouts.
Accept both :with_scores and :withscores as argument to sorted set commands.
Use hiredis (v0.3 or higher) by requiring "redis/connection/hiredis".
Use em-synchrony by requiring "redis/connection/synchrony".

See commit log.