Benchmark:
running
        IO, castaway, demerhpq, merlyn, browserUK
, each for at least 5 CPU seconds
...
IO:  1 wallclock secs ( 1.09 usr +  0.01 sys =  1.10 CPU) @ 37.27/s (n=41)
browserUK:  1 wallclock secs ( 1.04 usr +  0.01 sys =  1.05 CPU) @ 113.33/s (n=119)
castaway:  1 wallclock secs ( 1.07 usr +  0.00 sys =  1.07 CPU) @ 103.74/s (n=111)
demerhpq:  1 wallclock secs ( 1.07 usr +  0.00 sys =  1.07 CPU) @  3.74/s (n=4)
merlyn:  1 wallclock secs ( 1.04 usr +  0.01 sys =  1.05 CPU) @ 187.62/s (n=197)

            Rate  demerhpq        IO  castaway browserUK    merlyn
demerhpq  3.74/s        --      -90%      -96%      -97%      -98%
IO        37.3/s      897%        --      -64%      -67%      -80%
castaway   104/s     2675%      178%        --       -8%      -45%
browserUK  113/s     2932%      204%        9%        --      -40%
merlyn     188/s     4919%      403%       81%       66%        --