The MODS Editor has occupied my development time lately, and has reached a state approximating completion. I’ve posted about it here and here in the distant past. It is built with the Cocoon Forms framework, and provides full editing functionality in the browser. It now has a localization mechanism, which allows you to modify the form for a particular project by means of a simple configuration file. This will be important in my environment, where new projects pop up from time to time with unique requirements for a convenient metadata creation form. The MODS Editor localization feature will allow me to keep the main form definition untouched; the localization configuration is used to generate an XSL stylesheet on the fly, which is applied on the fly to the form definition files. Currently it allows you to remove elements and fields that you don’t want (which is all you need to customize the form, since it already contain all MODS elements and fields except mods:extension), and to add selection lists to particular fields. In the future I intend to add the ability to provide validation rules, control the layout of the form, and so on.
You can try it out at the MODS Editor demo; the code is available there under a GPL 3.0 license. And there is reasonably complete documentation.
There’s more and more competition in this space in the FLOSS world: Winona Salesky (The DIL) has done great things with XForms, and the forthcoming Metadata Toolkit build by Mark Jordan and team for the Alouette Canada project on the basis of the Qubit toolkit will be tremendous. So if you’re not already a Cocoon user, this may not be the shortest available route to a full-featured MODS editor for your project. But if you like the idea of starting with a full MODS form and easily trimming out the bits you don’t need for each project on your plate, give it a look.