iGal is a Perl-based program that can generate and publish an entire online
picture show (HTML slides, thumbnails and index page included) with just one
command line invocation in a Linux or Unix environment.   If you've got a 
directory (or several) full of image files that are waiting to be put online 
and shared with friends, then iGal is for you.

Features

 * flexible, well-documented 
 * handles JPG and GIF images 
 * 99% configurable through command line options and two HTML template files 
 * generated slides use a javascript trick to preload the next image in the
   slide show (great for those viewing your gallery over slow connections) 

WWW: http://www.stanford.edu/~epop/igal/