mod_dav enables Apache to understand the WebDAV protocol (extensions to HTTP). WebDAV stands for "Web-based Distributed Authoring and Versioning", and is defined by RFC 2518. WebDAV is intended to replace proprietary authoring protocols such as those used by Frontpage or NetObjects' Fusion, but is also a complete set of protocols for manipulating a webserver's files and directories, and their properties.
JEL (Java Expressions Library) is a library for evaluating simple single-line expressions in Java. The key feature of JEL is the fact that it is a compiler. The language of JEL expressions resembles the Java Language expressions as close as possible. JEL supports all Java primitive types and classes (even in the form of constants), allows one to call both static and virtual methods of Java classes (with no additinal runtime costs and no wrappers), and performs evaluation of constant subexpressions at a compile time.
jEdit is an Open Source text editor written in Java. It has many useful features, such as syntax highlighting, bracket matching, regular expression searching, multiple file search and replace, folding, and keyboard macros. jEdit also includes a powerful plugin architecture that allows more than 80 plugins to be downloaded and installed from within the editor.
Jigsaw is W3C's leading-edge Web server platform, providing a sample HTTP 1.1 implementation based on RFC2616 and a variety of other features on top of an advanced architecture implemented in Java. Jigsaw provides both client and server HTTP/1.1 implementations, is fast, easy to extend, flexible, and is also packaged as a ready-to-run HTTP/1.1 proxy-cache.