GimpFX Foundry | free scripts to expand GIMP

"This set contains different scripts for the creation of effects such as the old picture, lomography, image stylization, creation of all possible meshes and frames for pictures. It also contains scripts that significantly extend GIMP options when working with layers.
The set includes a huge number of scripts for work with image color; there are the scripts for total picture editing, creation of inner shadow, picture sphere and many other effects." [1]
(Link)

Geeqie | free image management software

"Geeqie is an image viewer that makes navigation of images easy. Images can be viewed full screen, and a slide show function allows automatic changing of the displayed image.
Geeqie is an image manager, with complete copy, move, rename, and delete functions available at the press of a button. Find the right image with the search feature. Image collectors can free up space with a function that finds duplicate images.
The one thing Geeqie is not, and never will be, is an image editor. However, Geeqie paired with an image editor, such as the Gimp, can be a very powerful combination."

(Link)

UFRaw | raw image editor

"UFRaw (which stands for Unidentified Flying Raw) is an application which can read and manipulate photographs in raw image formats, as created by many digital cameras. UFRaw used to be available both as a stand-alone program and as a GIMP plugin. However, since UFRaw-0.19, the GIMP plugin is no longer officially supported. As a stand-alone program, UFRaw can be invoked with a graphical interface, or as a command line batch processing utility.[1] UFRaw reads raw images, using dcraw as a back end, and supports color management via LittleCMS, allowing the user to apply input, output, and display color profiles (see also Linux color management). Thanks to dcraw's versatility, UFRaw supports nearly all of the numerous raw image formats used by digital camera manufacturers." [1]
(Link)

Mahara | ePortfolios

Mahara is an open source ePortfolio and social networking web application originally created by the government of New Zealand. It provides users with tools to create and maintain a digital portfolio of their learning, and social networking features to allow users to interact with each other. Mahara content management system provides users with blogs, a resume builder, a file manager and a view creator - a tool to help users create arrangements of their content in a particular way for others to see.

The eportfolio site http://myportfolio.school.nz, provided by the New Zealand Ministry of Education, free-of-charge for all New Zealand schools, is powered by Mahara

Digikam: photo management made easy

I'm a big fan of Picasa. My only quibble with it is that it's not open and is another way for Google to own your ass (or at least all your embarrassing photos). For quite a while I've been looking for a good photo management tool that has powerful batch processing support and I've certainly found one: digikam.

There is quite a list of open source, linux-friendly photo organisers: F-spot, Shotwell etc. but most of them have either no batch processing support or very limited support. Digikam is different and will probably satisfy all of your batch and manage dreams.

It does what it says on the box:

• import pictures
• organize your collection
• view items
• edit and enhance
• create (slideshows, calendar, print, ...)
• share your creations (using social web services, email, your own web gallery, ...)

Fast contact sheets for photos

Fast post this one: if you want to print contact sheets of a whole bunch of photos, do it using GQView. You can customise every aspect of the print job, from the labels printed underneath each image to the layout and rotation of thumbnails.