Readings on Web Software

"Web Server Workload Characterization: The Search for Invariants."
Martin Arlitt and Carey Williamson

"Key Differences between HTTP/1.0 and HTTP/1.1"
Balachander Krishnamurthy, Jeffrey C. Mogul, and David M. Kristol.

"Flash: An efficient and portable Web server"
Vivek S. Pai, Peter Druschel, Willy Zwaenepoel

And, the mother of all papers in this field is basically the
"RFC", which clocks in at 176 pages.