Classifications
General
Structured programming reference
The FXT Library
OpenLDAP guide
Web
The W3 Consortium
Web development tutorials
Web development quick reference
Javascript Linux (bellard.org, jor1k)
SQLPage
Java
J2SE 1.4 API
J2EE 1.4 API
J2SE 1.5 API
MID Profile basic and gaming
JUnit API
Struts 2 API and documentation
WebWork2 API and OGNL documentation
The Java Advanced Imaging (JAI) API
The Java Tutorial