Raindrops is a real-time stats toolkit to show statistics for Rack HTTP
servers. It is designed for preforking servers such as Rainbows! and
Unicorn, but should support any Rack HTTP server under Ruby 1.9, 1.8
and Rubinius on platforms supporting POSIX shared memory. It may also
be used as a generic scoreboard for sharing atomic counters across
multiple processes.

Homepage:
http://raindrops.bogomips.org/
