We need to get rid of some closed source and ugly icons and choose/create some consistent iconset for Admin panels and other icons.
For example, this icon:
(http://themes.tikiwiki.org/https://themes.tiki.org/show_image.php?id=55)
It seems to be an icon taken from WindowsXP and converted to gif which brings licensing issue.
Preferred format should be indexed (max. 256 colors) or alpha transparent PNGs with background colour set to white (when alpha it renders with white background in MSIE, instead some ugly grey or black background). Also when PNG is in indexed palette of same colour amount it gives better compression results than traditional GIF.
Freely Available Iconsets (must be LGPL or compatible to be shipped with Tiki)
Crystal Clear by Everaldo
http://www.kde-look.org/content/show.php?content=25668
License: LGPL
See also: http://commons.wikimedia.org/w/index.php?title=Category:Crystal_Clear_icons
Icons for Tiki by G. Ferreira
http://tikiwiki.org/gferreira_IconsTikiwiki
License: Unknown
Nuvola by David Vignoni
http://www.kde-look.org/content/show.php?content=5358
License: LGPL
Pros: very professionaly done
Cons: someone may find them too colourful (candy)
Tango Iconset
http://tango.freedesktop.org/Tango_Icon_Gallery
License: Creative Commons Attribution Share-Alike license
Mark James - Silk Icons
http://www.famfamfam.com/
License: Creative Commons Attribution 2.5 License
Monochrome Icons
http://www.kde-look.org/content/show.php?content=18317
License: LGPL
Pros: very accessible, could be used together with gferreira icons
Cons: someone may find them ugly
Note: Coloured version is called "Primary" and can be found here:
http://www.kde-look.org/content/show.php?content=39469
Glaze Icons
http://www.kde-look.org/content/show.php?content=23966
License: LGPL
Jini Iconset
mose found some LGPLed iconset on art.gnome.org too, which is called Jini (?)
game-icons.net
Font Awesome
The iconic font designed for use with Twitter Bootstrap
http://fortawesome.github.com/Font-Awesome/
Iconic
Iconic is an open source icon set consisting of 171 marks in raster, vector and font formats.
See Also
http://tiki.org/tiki-directory_browse.php?parent=103
http://tiki.org/tiki-index.php?page=IconReview
Resources
Icon set listings
http://linux.softpedia.com/get/Desktop-Environment/Icons/
http://www.maxpower.ca/free-icons/2006/03/05/
http://www.fiftyfoureleven.com/resources/icons