Google is running their Summer of Code (http://code.google.com/soc/2008/) program again this year, and Horde will apply to be a mentoring organization. This page is a guide to participating with Horde, and the place to collect ideas for projects. It is mainly for those with project ideas and those interested in participating as a student. If you'd like to help out by mentoring, send a note to Horde's mentor coordinator, Chuck Hagenbuch (chuck at horde dot org).
Create a Horde module which allows users to create, WYSIWYG edit, store, and print (via PDF) HTML documents.
Extend VFS to optionally support metadata attributes (such as category, description, license, version etc.) Attributes should be stored through a driver interface to allow later driver development like access to Documentum etc. The project should include a small Horde application to basically browse, search, and edit attributes - basically a very small document management system. This application would also serve as an example for implementing metadata in other applications.
Follow up on last year's Horde_Form project (currently available in the incubator - http://cvs.horde.org/incubator/Horde_Form/). Update the code to use Prototype and Scriptaculous for the scripting basis, sync with the current Horde_Form code, and go from there. The ability to have any form switch between active and inactive rendered mode - optionally on a field-by-field basis - using in-place-edit functionality would be very slick.
Develop a Horde application for managing SSL certificates. Possible functionality includes managing server certificates (for https, imaps, etc.) for administrators, and also allowing users to create end-user certificates for authentication and mail signing. For a bonus, integrate the user certificates with IMP to create a complete PKI management app.