FastCGI version of gallery
I have created a modified version of Apache::Gallery. It is extremely fast also on poor hardware. You can find this project here: fastcgi-gallery (http://freshmeat.net/projects/fastcgigallery/). If you are interested, here is a demo of FastCGI version of Apache::Gallery: fastcgi gallery demo (http://rajo.platon.sk/index/en/show,gallery)
Pro & Cons
Ideal for simple screenshot albums if you don't need user comments, view counts, ratings and other extras.
Does not fit if your albums contain pictures of many sizes and you want to show the actual size of each one of them.
An open, cross-platform journaling program.
A scientific plotting package.