OPML Manager displays OPML files as a folder tree that can be edited with a click of a mouse. The Manager lets users edit, add and delete nodes and links.
Web dialog boxes guide user data input:

An import option is available, so the site can work with existing OPML files. The site also provides hosting for OPML files and statistics for activity. Users can export their OPML and use it with any application, site or host.
Source: OPMLManager.com