100 concurrent requests with ~10KB script:
                     Requests Correct  Requests Error     AVG_msec
Apache 2.4/FCGI            202510             0               14
Apache 2.4/FastCGI/Plack    25584             0              116
Plack standalone            17012             0              175
Apache 2.2/mod_perl          1828          1128              185

100 concurrent requests with ~650KB script:
                     Requests Correct  Requests Error     AVG_msec
Apache 2.4/FCGI             55697             0               52
Apache 2.4/FastCGI/Plack    13971             0              213
Plack standalone            13042             0              228
Apache 2.5/mod_perl          1689             0              217