Publishing an extension on PEM
License
A Piwigo plugin depends on Piwigo core. It relies on Piwigo core functions and is considered as a "derivative work" which implies being released under a GPLv2 compatible license. For example GPLv2 (obviously) or MIT.
Even if you don't publish your plugin on PEM, please understand that your Piwigo must still be compatible with GPLv2 license. If you create a plugin for a client of yours, you have to publish is under a GPL-compatible license.
Actual publishing
Once you extension is ready you can publish it via the Piwigo extension manager (PEM).
Either create an account or login. On your user page, accesible via clicking on your username in the menu you need to add an extension with a name and a category
The success message contains a link directly to the extension page.
On this page you can edit all information relative to the extension (image, description, authos ...) These are accessible via the edit mode switch at the top of the page.
To be able to publish the extension a revision is needed. Before adding a revsion you need to add the svn/git configuration. We strongly suggest having the extension in a github repository.
Once saved some other svn/git settings are automaticlaly filled. There should be no need to changes these settings. The only one that could be modified is the Archive root directory which should be the ID of the plugin defined in main.inc.php of the plugin code
The next step is to add a revision
Except for a few plugins, the plugins versions should be name using the current version of piwigo followed by alphabetical letters for each new version. With each new Piwigo version the main number of the extension version should also change. For example: 16.a, 16.b, 17.a, 17.b, 17.c, 18.a ...etc
Once at least one revision exists the extension is published and any Piwigo user can add it to their Piwigo via the administration interface.