JPEG

Implementation of the JPEG2000 Standard in Java
A collaborative project to produce a Java implementation, including verification against a standard.
http://jj2000.epfl.ch/

Independent JPEG Group
The Independent JPEG Group (IJG) is a group that writes and distributes a widely used free and open source library for JPEG image compression.
http://www.ijg.org/

JPEG FAQ
A collection of frequently asked questions with answers from Usenet about JPEG.
http://www.faqs.org/faqs/jpeg-faq/

JPEGclub.org
Provides information and several tools for lossless transformation of JPEGs.
http://jpegclub.org/

Online JPEG Compressor
A tool to compress JPEGs.
http://www.chami.com/jc/