Recently, I was doing some work to make sure that the OPML files I created using Drummer and available via Drummer were available from my site instead of drummer.scripting.com. My initial effort was using code from the outlineBrowser2 and opmlPackage repos from Dave Winer. After reviewing the code, I felt that I could focus more on using the outlineBrowser2 application. I also wanted to remove dependency on jQuery and any other hosted files (got Claude to help me with that….).
My updated viewer is now available on Github (opml-outline-viewer). The README file covers how to use the viewer to view multiple files. The rendering of the OPML file bolds each top-level headline, and uses triangle icons to expand/collapse outline elements. The default is to render the file with all headlines expanded. There is a function that allows the user to modify this behavior in code.js (collapse_everything), which is currently commented out.
Give it a try – let me know what you think!