Publish on Gallery is a plug-in for Windows Live Photo Gallery (WLPG) that enables publishing to PHP Gallery (http://gallery.menalto.com). It currently supports publishing photos directly to Gallery2. An equivalent plugin for Gallery 3 is available here.
Licence and Cost
Publish on Gallery is open source and available for no cost under the MIT Licence. To support this project you can make a small donation by clicking the donate button.