Linux

http://sial.org/howto/openssh/publickey-auth/ notes on setting up SSH pubic key auth

http://www.fishpool.org/post/2008/03/31/Optimizing-Linux-I/O-on-hardware-RAID explains use linux IO scheulers with presence of smart RAID controllers.

http://www.opennet.ru/base/net/adsl_shaper.txt.html shaper script for ADSL< -->Ethernet gateway

http://forum.nginx.org/read.php?2,2073 some notes about keep-alive proxy setup for apache

http://forum.nginx.org/read.php?2,1008,page=1 post on nginx forum that provides some insights about central logging / log collections

http://fasterdata.es.net/TCP-tuning/ Excellent site provides both theoretical background and practical recommendation for the situation when you need to push limits of TCP links using regular OS and commodity hardware. Especially useful if you need to do it via long-haul fast TCP link, i.e. the situation when you normally use specialized networking hardware (read: cisco)

http://tigervnc.org/ likely to be a replacement for tightvnc (better performance )

http://www.netbsd.org/~ad/50/img0.html BSD 5.0 release presentation, includes benchmarks: F10 vs FreeBSD 7.x vs NetBSD 4.0 and 5.0 (also see http://lwn.net/Articles/330909/ )

https://bugzilla.redhat.com/show_bug.cgi?id=484667 issue with dropped packets on newer broadcomm ethernet cards, found in dell 1950III servers

http://www.gossamer-threads.com/lists/quagga/users/16802 email threads that provides some pieces of info about linux routing performance (from 2008 )