there's a very old one (that predates the current authentication provider framework): http://www.codeplex.com/DNNLDAP

Does that mean you're volunteering to do one and donate it to the core Carlos? I don't know the exact percentage but the majority of the projects (UDT, Repository, FCKEditor, AD Provider, etc.) started as stand-alone projects and were donated to the core project. I don't want to appear rude, and I'm sorry if I do, but I see lots of people asking for an LDAP provider but I don't see anyone stepping up and volunteering to do one. The projects are a volunteer effort. We don't make an income from DotNetNuke unless it's part of our business model so that means that the majority project leads/team members are working full time jobs and then coming home and working on DotNetNuke code in the evenings and on weekends. Add in family commitments and that doesn't leave a lot of time to create new projects.