album is a free HTML/XHTML photo album and gallery generator that supports themes/skins. You can choose different themes or write your own to get different layouts and styles. It creates all your thumbnails (including directory thumbnails) and descends into directories so you can organize your photos. See the home page for more examples. album is also multi-lingual, with many languages being added all the time. N.B.: The purchase link is provided for donations; the software does not cost anything.
cthumb allows you to create Web albums of digital pictures with thumbnails, captions, and several different views of the collection, including (optionally) several languages and resolutions. An album is composed of a series of pages, each composed of a collection of pictures. You can have several annotations per picture, and can customize almost everything in the way the albums look on the screen.
mp3riot (formerly known as f2html.pl) is a command line utility that searches recursively through directories, builds a file list (with additional file information), and generates HTML files, playlists, etc. The output can be controlled, links can be corrected, and more. The script is mainly desigend to create Web pages, playlists, and databases for MP3 and Ogg files, but can also used for other purposes.
graphviz is a set of graph drawing tools and libraries. It supports hierarchical and mass-spring drawings; although the tools are scalable, their emphasis is on making very good drawings of reasonably-sized graphs. Package components include batch layout filters and interactive editors for X11, Java, and a TCL/tk extension. The batch filters can be configured as a web visualization service (using GIF and click-maps). Typical applications include display of finite state machines, software diagrams, database schemas, and communication networks.