The folowing programs and libraries has been used for DPortal CMS:

Smarty (Template Engine, LGPL): http://smarty.net

FPDF Library (When using DBook): http://fpdf.org

TinyMCE (WYSIWYG Editor, GPL): http://tinymce.moxiecode.com

CSS Dock Menu: http://www.ndesign-studio.com/blog/design/css-dock-menu

Highslide JS (for Gallerires, Dual-licensed): http://highslide.com

Documentation:

Apache2 Documentation: http://httpd.apache.org/docs/2.2

Smarty Documentation: http://smarty.net/manual/

Books for learn more about PHP:

Anaya multimedia (Information books, spanish only): http://www.anayamultimedia.es