“The first, VelociGen 1.1, is from Binary Evolution Inc., of
Rancho Santa Fe, Calif., and is available now for $999 on Linux;
$1,699 on Windows NT; and $4,999 on Solaris, HP-UX, AIX and
Irix.”
Here’s an overview of commercial applications that increase
speed and stability of web servers. The product quotes above
includes a Linux port, with the lowest cost.