• The First WWW Conference '94
• The Second WWW Conference '94
• The Third WWW Conference '95
• The Fourth WWW Conference '95
• The Fifth WWW Conference '96 [lost link]
• The Sixth WWW Conference '97 [lost link]
• The Seventh WWW Conference '98 [lost link]
• The Eighth WWW Conference '99
• The Ninth WWW Conference '2000
• The 10th WWW Conference '2001
• WWW2002
• WWW2003
• WWW2004
• WWW2005

Conference proceedings by series (some free):

• ACM HyperText (HT)
• ACM Digital Libraries (DL)
• ACM SIGIR
• ACM KDD
• Very Large Data Bases (VLDB)
• ACM CIKM (Conference on Information and Knowledge Management)
• ISOC INET
• ACM SIGMOD/PODS

Miscellaneous (mostly free):

• Hypertext, Information Retrieval, Multimedia (HIM '97)
• USITS97 - USENIX Symposium on Internet Technologies and Systems
• Advances in Digital Libraries '98 
• WebDB'99 - Web and Databases 
• ML4IE - Machine Learning for Information Extraction '99 
• CoLIS3 - 1999 abstracts 
• Recommender Systems 1999: Algorithms and Evaluation 
• WEBKDD '99 - Web Usage Analysis and User Profiling 
• USITS99 - USENIX Symposium on Internet Technologies and Systems
• DL'95 (free)

• The ACM Digital Library
• IEEE Computer Society - Conference Proceedings

email comments to einat at webir.org