Web frameworks benchmark.

Recent results for the string rendering (rps = requests per second):

  Sinatra => 874.26 rps
  MerbVeryFlat => 783.36 rps
  Merb => 711.92 rps
  Camping => 612.93 rps
  Ramaze => 532.59 rps
  Rails => 370.88 rps

Memory footprint after 1000 requests (Kb):

  Sinatra        => 15128
  Camping        => 21172
  Merb very flat => 31916 = 18836 worker + 13080 master 
  Ramaze         => 33624 = 24460 worker + 9164 ramaze_monitor 
  Rails          => 35248
  Merb           => 48664 = 27364 worker + 21300 master

Notes: 
1. In a cluster of 4 processes merb beats Camping, Ramaze and Rails (only worker size is important).
2. Difference gets smaller when you add your fat application code and libraries (rmagick etc.)