Oracle Technology Network: PL/SQL
Official product documentation, white papers, technical briefs, feature lists.
BNF Index of PL/SQL Version 2.1 for Oracle 7
Backus-Naur Notation for PL/SQL 2.1 for Oracle 7. Old version, but still interesting.
Code Samples and Suggestions
Over a dozen tips, tricks, and code samples, by Jonathan Lewis.
High Speed PLSQL
NOUG presentation on High Speed PLSQL Tuning by Rodger Lepinsky.
Ixora Q & A
Questions with answers by Steve Adams, expert on Oracle internals
Message board on orafaq.net
Unmoderated questions and answers.
Part of the Oracle FAQs, this is a brief but useful list of PL/SQL questions and answers.
Short tips and code fragments written (or collected) by Connor McDonald. Includes bit operations, undocumented features, and 8.1.7.
An open source, focused, common repository for PL/SQL developers. Intended to improve the day-to-day life of thousands of Oracle developers around the world.
Encyclopedia article about the Oracle extension to SQL, including an overview of its functionality, data types, and constructs.
An Apache module. It aims to provide Oracle Web Application Server 3.0 API compatible interface to Oracle RDBMS. Tested with Oracle8/8i.